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PREFACE
PT6A-60 SERIES TRAINING MANUAL November 2007
Pratt & Whitney Canada © 1999-2007 Pratt & Whitney Canada, Inc.
STUDENT: ________________________________ INSTRUCTOR:_____________________________
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PREFACE I
DISCLOSURE
WARNING - PROPRIETARY RIGHTS NOTICE This document is the property of Pratt & Whitney Canada Corp. “(P&WC)”. You may not possess, use copy or disclose this document or any information in it, for any purpose, including without limitation to design, manufacture or repair parts, or obtain FAA or any other government approval to do so, without P&WC’s express written permission. Neither receipt or possession of this document alone, from any source constitutes such permission. Possession, use, copying or disclosure by anyone without P&WC’s express written permission is not authorized and may result in criminal or civil liability NOTICE - DISCLOSURE OF INFORMATION This document contains trade secrets or other confidential information, the further disclosure of which may be harmful to Pratt & Whitney Canada Corp. if the head of a government agency or department intends to disclose any of this information, written notice should be given to: the Vice President - Legal Services, Pratt & Whitney Canada Corp., 1000 Marie Victorin (01BE5), Longueuil, Quebec J4G 1A1
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PREFACE II
PRATT & WHITNEY CANADA The Customer Training Centre, Pratt and Whitney Canada, Longueuil, Quebec, Canada issued this document. This document is to be used for Training Use Only. The data contained herein does not replace or supersede the information contained in the appropriate airframe or engine maintenance manuals or other official publications. For information concerning this manual, contact the P&WC Customer Training Department, by : Tel: 1-450-468-7774, Fax: 1-450-468-7824, or Email: [email protected] P&WC Customer Training course schedule and registration on Internet: http://www.pwccustomertraining.ca For technical queries, contact the P&WC technical support Customer First Centre (CFC) (24 HOUR SERVICE): Telephone : (USA & Canada)1-800-268-8000 International Direct Access :1-8000-268-8000 General :1-450-647-8000 Fax :1-450-647-2888 Pratt & Whitney Canada on the Internet : http://www.pwc.ca
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PREFACE III
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PREFACE IV
TABLE OF CONTENT PREFACE ............................................................ I DISCLOSURE...................................................... II PRATT & WHITNEY CANADA............................. III-IV TABLE OF CONTENT.......................................... V-VIII INTRODUCTION ................................................. IX SCOPE ................................................................ X ABBREVIATIONS ................................................ XI ENGINES COVERED IN THIS MANUAL ............ XII PT6 GENERAL NOTES ....................................... XIII MAJOR ENGINE DIFFERENCES ....................... XIV-XV P&WC PUBLICATIONS ....................................... XVI PUBLICATION STANDARDS............................... XVII-XVIII SERVICE BULLETIN COMPLIANCE CODES..... XIX CHAPTER 1 - ENGINE OVERVIEW.................... 1.1 PT6A-61 RIGHT FRONT VIEW ........................... 1.2 PT6A-64 LEFT FRONT VIEW ............................. 1.3 PT6A-60 RIGHT FRONT VIEW ........................... 1.4 PT6A-67 LEFT VIEW........................................... 1.5 MAJOR ASSEMBLIES AND FLANGES .............. 1.6-1.7 FEATURES .......................................................... 1.8 GENERAL TURBOPROP OPERATION .............. 1.10 TURBOPROP ENGINE ....................................... 1.11 MAIN ENGINE BEARINGS.................................. 1.12 BEARINGS .......................................................... 1.13 STATIONS............................................................ 1.14-1.15 ENGINE EXTERNAL COMPONENTS ................ 1.16-1.19
COMPRESSOR INLET CASE ............................. 2.6-2.7 COMPRESSOR ................................................... 2.8-2.9 COMPRESSOR WASH ....................................... 2.10-2.11 COMPRESSOR BLEED VALVE .......................... 2.12-2.15 PRE-SWIRL SYSTEM ......................................... 2.16-2.19 BLEED VALVE CLOSING POINT ........................ 2.20-2.23 GAS GENERATOR CASE ................................... 2.24 GAS GENERATOR CASE / DIFFUSER .............. 2.25 COLD SECTION TROUBLESHOOTING ............. 2.26 CHAPTER 3 - COMBUSTION & TURBINE ........ 3.1 HOT SECTION..................................................... 3.2 HOT SECTION AREA.......................................... 3.3 COMBUSTION CHAMBER LINER & SMALL EXIT DUCT .......................................... 3.4-3.5 COMPRESSOR TURBINE VANE RING.............. 3.6-3.9 COMPRESSOR TURBINE .................................. 3.10-3.11 COMPRESSOR TURBINE TRIM BALANCING... 3.12 COMPRESSOR TURBINE .................................. 3.13 ALTERNATE TRIM WEIGHTS (64/66/67)............ 3.14 ALTERNATE TRIM WEIGHTS ............................. 3.15 POWER TURBINE VANE RINGS ........................ 3.16-3.17 POWER TURBINES ............................................ 3.18-3.19 TURBINE WASH.................................................. 3.20-3.21 EXHAUST DUCT & PT SHAFT HOUSING.......... 3.22-3.23 HOT SECTION SEALING .................................... 3.24-3.27 HOT SECTION TROUBLESHOOTING................ 3.28
CHAPTER 2 - COMPRESSOR SECTION .......... 2.1 COMPRESSOR SECTION .................................. 2.2-2.3 INERTIAL SEPARATOR (AIRFRAME)................. 2.4 INERTIAL SEPARATOR (TYPICAL) .................... 2.5 PT6A-60 SERIES
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TABLE OF CONTENT V
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TABLE OF CONTENT (CONT’D) CHAPTER 4 - GEARBOXES............................... 4.1 REDUCTION GEARBOX ..................................... 4.2-4.3 STANDARD ROTATION REDUCTION GEARBOX4.4 PT6A-66 REVERSE ROTATION GEARBOX ....... 4.5 ACCESSORY GEARBOX .................................... 4.6-4.7 PIN LOCK ARRANGEMENT ............................... 4.8 ACCESSORY GEARBOX .................................... 4.9 CHAPTER 5 - OIL SYSTEM................................ 5.1-5.7 OIL PRESSURE REGULATION & FILTRATION.. 5.8-5.9 THERMOSTATIC BYPASS & CHECK VALVE ................................................. 5.10-5.11 OIL SYSTEM TROUBLESHOOTING .................. 5.12-5.13 CHAPTER 6 - SECONDARY AIR SYSTEM........ 6.1-6.3 ACCESSORY GEARBOX BREATHER ................ 6.4-6.5 OIL TANK PRESSURIZING VALVE ..................... 6.6-6.7 TURBINE COOLING AND AIRBLEED SYSTEM................................... 6.8-6.9 BEARING COMPARTMENT SEALING ............... 6.10-6.11 CHAPTER 7 - ENGINE INDICATING SYSTEM .. 7.1-7.3 INTER-TURBINE TEMPERATURE (T5).............. 7.4 TEMPERATURE INDICATING SYSTEM (T5) ..... 7.5 TEMPERATURE INDICATING SYSTEM (ITT) .... 7.6 T5 SYSTEM SCHEMATIC ................................... 7.7 TORQUE SYSTEM .............................................. 7.8-7.9 CHIP DETECTOR................................................ 7.10-7.11
PT6A-60 SERIES
CHAPTER 8 - IGNITION SYSTEM.................. 8.1 IGNITION SYSTEM ......................................... 8.2-8.3 CHAPTER 9 - PERFORMANCE ..................... 9.1-9.2 ENGINE PERFORMANCE CHECK (TYPICAL)9.3 PERFORMANCE CHECK (SHORTS INSTALL)9.4-9.6 WebECTM........................................................ 9.7-9.8 ECTM SAMPLE PLOT ..................................... 9.9 TBO & HSI INTERVAL ..................................... 9.10 OPERATING LIMITS* ...................................... 9.11-9.18 ROTOR COMPONENTS - SERVICE LIFE ...... 9.19 OVERTORQUE CHART (TYPICAL) ................ 9.20 OVERTEMPERATURE CHART (TYPICAL)..... 9.21 ENGINE TROUBLESHOOTING ...................... 9.22 PERFORMANCE TROUBLESHOOTING ........ 9.23-9.27 CHAPTER 10 - FUEL SYSTEM ...................... 10.1 POWER MANAGEMENT ................................. 10.2-10.3 FUEL SYSTEM ................................................ 10.4-10.6 FUEL SYSTEM SCHEMATIC .......................... 10.7 FUEL HEATER................................................. 10.8-10.9 FUEL PUMP .................................................... 10.10-10.11 FUEL CONTROL UNIT (MAIN FLOW) ............ 10.12-10.13 FUEL METERING SECTION ........................... 10.14-10.15 METERING SECTION (3D CAM) .................... 10.16 FUEL CONTROL SYSTEM.............................. 10.17 COMPRESSOR DELIVERY AIR LINES .......... 10.18 P3 AIR FILTER ELEMENT............................... 10.19 FLOW DIVIDER WITH DUMP VALVE.............. 10.20-10.21 FLOW DIVIDER WITH PURGE VALVE ........... 10.22-10.23 FLOW DIVIDER WITH DUMP VALVE.............. 10.20-10.21
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TABLE OF CONTENT VI
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TABLE OF CONTENT (CONT’D) FLOW DIVIDER WITH PURGE VALVE ............10.22-10.23 SIMPLEX FUEL NOZZLES...............................10.24-10.25 DUPLEX FUEL NOZZLES................................10.26-10.27 FUEL CONTROL UNIT MANUAL OVERRIDE .10.28 FCU MANUAL OVERRIDE ...............................10.29 POWER RECOVERY SYSTEM........................10.30-10.31 OVERTORQUE LIMITER..................................10.32-10.33 FUEL CONTROL UNIT ADJUSTMENT............10.34-10.35 FUEL SYSTEM TROUBLESHOOTING SUMMARY...................10.36 CHAPTER 11- PROPELLER SYSTEM............11.1-11.3 PITCH CHANGE MECHANISM........................11.4-11.5 PROPELLER GOVERNOR GOVERNING MODE ........................................11.6-11.7 PROPELLER GOVERNOR...............................11.8 BETA MODE (FORWARD OPERATION)..........11.9 PROPELLER GOVERNOR...............................11.10-11.12 BETA MODE (REVERSE OPERATION)...........11.13 PROPELLER FEATHERING.............................11.14-11.15 NF GOVERNOR ...............................................11.16-11.17 PROPELLER OVERSPEED GOVERNOR .......11.18-11.19 PROPELLER GOVERNOR ADJUSTMENTS ...............................................11.21-11.23 PRIMARY BLADE ANGLE (PBA) CHECK........11.24 PRIMARY BLADE ANGLE CHART ..................11.25 PROPELLER SYSTEM TROUBLESHOOTING11.26
HOT SECTION TOOLS.................................... 12.8-12.9 CT TIP CLEARANCE MEASUREMENT.......... 12.10 HOT SECTION INSPECTION (CONT’D)......... 12.12 CT BLADE SULPHIDATION ............................ 12.13 HOT SECTION INSPECTION (CONT’D)......... 12.14-12.19 CHAPTER 13 - RIGGING ................................ .13.1 BASIC ENGINE RIGGING ............................... 13.2 REAR LINKAGE RIGGING .............................. 13.3 WOODWARD FUEL CONTROL RIGGING...... 13.4 REAR LINKAGE (WOODWARD) ..................... 13.5 FRONT LINKAGE RIGGING............................ 13.6 FRONT LINKAGE ............................................ 13.7 FUEL CONDITION LEVER .............................. 13.8 FUEL & PROPELLER LEVER RIGGING......... 13.9 POST RUN UP ADJUSTMENTS ..................... 13.10-13.11 TWIN ENGINE RIGGING TROUBLESHOOTING ..................................... 13.12 POST RUN-UP ADJUSTMENTS (TWIN ENGINE)............................................... 13.13
CHAPTER 12 - MAINTENANCE PRACTICES.12.1 PERIODIC INSPECTION..................................12.2-12.3 HOT SECTION INSPECTION ..........................12.4 BORESCOPE INSPECTION ............................12.6 GUIDE TUBE ORIENTATION ...........................12.7 PT6A-60 SERIES
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TABLE OF CONTENT VII
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TABLE OF CONTENT VIII
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INTRODUCTION
INTRODUCTION
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INTRODUCTION IX
SCOPE This training guide contains information pertaining to the description, operation, maintenance and troubleshooting of the PT6A-52 /60A / 60AG / 61 / 64 / 65AG / 65AR / 65B / 65R / 66 / 66A / 66B / 66D / 67 / 67A / 67AF / 67AG / 67AF / 67AR / 67B / 67D / 67F / 67P /67R engines. This training guide is intended for training use only and includes cross section drawings, schematics and text. A basic understanding of jet engine principle would be an asset. This guide may be used for Line Maintenance or Heavy Maintenance training.
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INTRODUCTION X
ABBREVIATIONS AG AGB AMM BOV CCW CW CSU CT ECTM ESHP FCU FI FOD GI HSI IAS IBR ISA ITT MM MOP MOT Nf Ng Np OAT OSG P0 P1 P2 P2.5 P3
Agricultural Accessory Gearbox Airframe Maintenance Manual Bleed Off Valve Counterclockwise Clockwise Constant Speed Unit (Prop Governor) Compressor Turbine Engine Condition Trend Monitoring Equivalent Shaft Horsepower Fuel Control Unit Flight Idle (High Idle) Foreign Object Damage Ground Idle (Low Idle) Hot Section Inspection Indicated Air Speed Integrally Bladed Rotor International Standard Atmosphere Interturbine Temperature (T5) Maintenance Manual Main Oil Pressure Main Oil Temperature Free Turbine Speed Gas Generator Speed (N1) Propeller Speed (N2) Outside Air Temperature Overspeed Governor Bypass Fuel Pressure Fuel Pump Delivery Pressure Metered Fuel Pressure Compressor (axial stage) discharge pressure (station 2.5) Compressor Discharge Pressure (Station 3)
PT6A-60 SERIES
Palt Pamb PBA PLA PPH PSI PSIA PSID PSIG PT Px Py RGB S/N SB SIL SFC SHP T/O T5 TBO Tq Wa Wf
Pressure Altitude Ambient Air Pressure Primary Blade Angle Power Lever Angle Pounds Per Hour Pounds Per Square Inch Pounds Per Square Inch Absolute Pounds Per Square Inch Differential Pounds Per Square Inch Gage Power Turbine Modified P3, After A Restrictor Modified Px, After A Restrictor Reduction Gearbox Serial Number Service Bulletin Service Information Letter Specific Fuel Consumption Shaft Horsepower Take-Off Temperature At Station 5 (ITT) Time Between Overhaul Torque Air Mass Flow Fuel Flow
Bold highlights indicate engine parameters
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INTRODUCTION XI
ENGINES COVERED IN THIS MANUAL
Engine Model
SHP
Weight (Lbs)
Certification Date
Aircraft
PT6A-52
850
430
April 2007
Blackhawk B200GT
PT6A-60A
1050
475
May 1983
Beech KA 300/350
PT6A-60AG
1050
500
May 1995
Air Tractor AT-602, Ayres
PT6A-61
850
429
March 1983
Piper Cheyenne IIIA
PT6A-64
700
472
April 1990
Socata TBM 700
PT6A-65B
1100
495
December 1992
Beech 1900 C
PT6A-65R
1376
496
August 1982
Shorts 360
PT6A-65AG
1300
501
March 1985
Air Tractor AT-602, Ayers Turbo Thrush
PT6A-65AR
1424
501
January 1984
Shorts 360
PT6A-66
850
469 & 483
July 1986
Piaggio Avanti
PT6A-66A
850
456
December 2003
AeroVodochody Ae 270HP
PT6A-66B
850
460
March 2006
Piaggio Avanti II
PT6A-66D
850
458
November 2005
TBM 850
PT6A-67
1200
520
November 1986
Beech Starship
PT6A-67A
1200
520
January 1988
Beech Starship
PT6A-67AG
1350
525
July 1998
Air Tractor AT-802AF
PT6A-67AF
1424
552
November 1987
Conair IMP S-2
PT6A-67B
1200
538
October 1990
Pilatus PC-12
PT6A-67D
1279
534
December 1991
Beech 1900 D
PT6A-67F
1600
550
June 2007
Air Tractor AT-1002
PT6A-67P
1200
550
September 2007
Pilatus PC12 Next Generation
PT6A-67R, A-67AR
1424
534
December 1991
Shorts 360, DC-3 (Conversion)
PT6A-67T
1400
535
November 2000
DHC-4A (Conversion)
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INTRODUCTION XII
PT6 GENERAL NOTES Initial Design ................................................... 1958 First Production Engine (PT6A-6, 550 SHP)... 1963 Engines Delivered........................................... 42338* Hours Accumulated......................................... 316 000 000* Certified Aircraft Applications.......................... 128 Different Operators ......................................... 6724 Different Countries .......................................... 171 * Numbers Current as of December 2006 The Birth Of Pratt & Whitney Canada: In June 1927 a Wright-powered Vedette flying boat crashed in a northern Quebec lake . The RCAF purchased the seaplane from the estate of the deceased pilot and installed the engine on a Douglas seaplane . The performance of the engine led to an order for additional powerplants , with the proviso that a Canadian facility be established to service the U.S. produced engines .
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INTRODUCTION XIII
MAJOR ENGINE DIFFERENCES The PT6A Engines Covered In This Manual Are Divided In 4 Groups: -
PT6A-52, 60A, 60AG, 61 PT6A-65B, A-65R, A-65AR, A-65AG PT6A-67, A-67A, A-67AF, A-64, A-66/A/B/D PT6A-67AG, A-67B, A-67D, A-67F and A-67P
Group 1: PT6A-52, A-60A, A-60AG, and A-61 PT6A-52: Similar to A-61 with higher ITT at take-off PT6-A60A: Reference model. Derived from PT6A-42 with A-45 type RGB (long RGB). PT6A-60AG: Agricultural version of A-60A. Manual override system on the fuel control unit. (long RGB). PT6A-61: Mechanically similar to A-60 with A-41 type RGB (short RGB). Group 2: PT6A-65B, A-65R, A-65AR and A-65AG PT6A-65R: Reference model. Similar to the PT6A-45R except for increased compressor airflow and pressure ratio (additional compressor stage). Automatic power recovery system on the fuel control unit. PT6A-65B: Similar to A-65R, no automatic power recovery system on the fuel control unit. PT6A-65AR: Similar to A-65R, new fuel control unit, longer compressor turbine blades for 4% increase in thermodynamic power. PT6A-65AG: Hardware derivative of A-65B. Engine ratings similar to A-65AR. No automatic power recovery system but a manual override system on the fuel control unit (if PT6A-60 SERIES
equipped and connected) Group 3: PT6A-67, A-67A, A-67R, A-67AF, A-64, and A-66/A/B/D The A-67 engines differ from the A-65 in the following manner: - Large compressor diameter for increased mass flow - Improved compressor turbine blades design - Modified compressor turbine vane ring and shroud segments - Redesigned power turbines - Light weight magnesium inlet case instead of aluminum - Light weight magnesium reduction gearbox case instead of aluminum for A-67 and A-67A - Reinforced reduction gearbox and bearing for A-67R and A-67AF) - Six engine mount pads instead of four - Improved fuel control unit design - Larger diameter propeller shaft flange - Electronic oil level indicator - Oil tank with oil level sight glass PT6A-67: Reference model. Derivative of A-65B with 10% increased flow and redesigned turbine. PT6A-67A:Mechanically identical to the A-67 but 5% increase in increase cruise rating. Pusher application. PT6A-67R:Mechanically similar to A-67A. Automatic power recovery system on the fuel control unit. Exhaust duct rotated 30º (Shorts only). PT6A-67AF:Derivative of A-67R with the automatic power recovery system blanked off.
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INTRODUCTION XIV
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MAJOR ENGINE DIFFERENCES (CONTINUED) Group 3: (continued) PT6A-66/B: Mechanically similar to A-67 with reduction gearbox capable of standard or reverse rotation (A-61 derivative, 2000 rpm). Flat rated at 850 SHP. Pusher application. PT6A-66D:Silimar to A-66. Single engine application. Flat rated to 850 shp. Manual override. PT6A-64: Mechanically similar to A-66 with A-61 reduction gearbox (2000 rpm). Manual override on the fuel control unit and a torque limiter on the reduction gearbox. Flat rated to 700 SHP. Single engine application. PT6A-66A: Mechanically similar to A-64 with A-64 reduction gearbox, A-66 propeller governor unit and A-67AG fuel control unit (manual override). Flat rated at 850 SHP. Single engine application.
PT6A-60 SERIES
Group 4: PT6A-67AG, A-67B, A-67D, A-67F and A-67P. The engines from this group include the following design modifications for increase power ratings: - Airflow increased through fine-tuning of the compressor blade airfoil. - Redesigned compressor turbines blades - Improved cooling of the compressor turbine vane ring - Compressible seals in the hot section ("W" and "C" seals) - Redesigned no. 1 bearing area - Redesigned reduction gearbox to withstand higher torque - P3 air seal on flange "C" - Exhaust case structurally strengthened PT6A-67AG: Agricultural version of the A-67R. Manual override on the fuel control unit. PT6A-67B: Mechanically similar to A-67A with increased capacity reduction gearbox. Single engine application. Manual override on fuel control unit, fixed speed propeller governor. Manual propeller overspeed governor reset/test function. Improved durability hot section. PT6A-67D: Mechanically similar to A-67B with A-67R reduction gearbox (lighter) and A-67 fuel control unit. PT6A-67F: Similar to A-67AG with higher take-off power and cruise rating. PT6A-67P: Similar to A-67B with faster climb and higher cruise speed, A-67A compressor and AGB backup generator pad.
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INTRODUCTION XV
P&WC PUBLICATIONS Pratt and Whitney Canada publish various documents and manuals to support all the engines in service. This is a brief description of the documents:
Training Manuals Training guides are published by the Customer Training Centre to assist the instructors in class.
Illustrated Parts Catalog (IPC) Publication Price List Contain all part numbers and parts history information along with identifying drawings for an engine series. To be used for ordering parts. Maintenance Manual (MM) The manual defines all the line and heavy maintenance tasks that can be done on the engine as well as various tests and adjustments. Service Bulletin (SB) Service bulletins are published to introduce new parts and modify existing parts to improve the product. - 13XXX series is used for the PT6A-52 / 60A / -61 / -65. -14XXX series is used for the PT6A-64 / -66 / -67.
The publication price list contains the prices of all P&WC publications and training material available to customers. For more information on Pratt & Whitney Canada publications contact: Supervisor, Publications Distribution 1000 Marie Victorin Longueuil, Quebec Canada J4G 1A1 Telephone: 1-450-647-2705 Fax: 1-450-647-2702 E-mail: [email protected]
Service Information Letter (SIL) Service information letters are produced by Customer Support to inform all operators on new techniques, new products and other general information. They are usually valid for a 1 year period.
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INTRODUCTION XVI
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PUBLICATION STANDARDS General: The engine manuals are published following the ATA 100 revision 15 The engine Maintenance Manual basic chapters and sections are:
The engine illustrated parts catalogue (IPC) basic chapters and sections are:
FRONT MATTER (TEMPORARY REVISION, SERVICE BULLETIN LIST) INTRODUCTION (TOOLS, CONSUMABLES) AIRWORTHINESS LIMITATIONS (LIFE LIMITED PARTS) 61 - 20 PROPELLER GOVERNING 70 - 00 STANDARD PRACTICES 71 - 00 POWER PLANT 72 - 00 ENGINE (GENERAL) 72 - 10 REDUCTION GEARBOX 72 - 20 AIR INLET SECTION 72 - 30 COMPRESSOR SECTION 72 - 40 COMBUSTION SECTION 72 - 50 TURBINE SECTION 72 - 60 ACCESSORY GEARBOX 73 - 00 ENGINE FUEL AND CONTROL 74 - 00 IGNITION SYSTEM 75 - 00 AIR SYSTEM 76 - 00 ENGINE CONTROLS 77 - 00 ENGINE INDICATING SYSTEM 79 - 00 OIL SYSTEM
61 - 20 72 - 00 72 - 10 72 - 20 72 - 30 72 - 40 72 - 50 72 - 60 73 - 10 73 - 20 74 - 10 74 - 20 75 - 30 76 - 10 77 - 20 79 - 20
PT6A-60 SERIES
PROPELLER GOVERNING ENGINE (SHIPPING) REDUCTION GEARBOX AIR INLET COMPRESSOR SECTION COMBUSTION SECTION TURBINE SECTION ACCESSORY GEARBOX ENGINE FUEL and CONTROL FUEL CONTROLLING IGNITION IGNITION SYSTEM AIR ENGINE CONTROLS ENGINE INDICATING SYSTEM OIL SYSTEM
Example: A basic chapter identified as: 72-40-01 72 Indicates the engine chapter 40 Indicates the combustion section 01 Indicates the combustion chamber liner
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INTRODUCTION XVII
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PUBLICATION STANDARDS (CON’T) Page blocks: The page block numbers of each chapter are used to separate the subjects within the manual for ease of reference.
The standard page blocks are as follows: CHAPTER APPLICABILITY
Description and Operation
Pages
61-20
1 to 99
X
Fault isolation
101 to 199
Maintenance Practices
201 to 299
Servicing
301 to 399
Removal/Installation
401 to 499
Adjustment/Test
501 to 599
Inspection/Check
601 to 699
Cleaning/Painting
701 to 799
Approved Repairs
801 to 899
70-00
71-00
72-00
All others
X
X
X X
X
X X
X
X X
X
X X
X
X X
X
Example: In chapter 73-10-05, page 201, you will find the maintenance practices for the fuel manifold and nozzles.
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INTRODUCTION XVIII
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SERVICE BULLETIN COMPLIANCE CODES Category 1 Do before the next flight. Category 2 Do the first time the aircraft is at a line station or maintenance base that can do the procedure. Category 3 Do before xxx hours or xxx cycles. This Category may be expanded as required, to specify a minimum and/or a maximum and/or repetitive interval/inspection. Category 4 Do this SB the first time the engine or module is at a maintenance base that can do the procedures, regardless of the scheduled maintenance action or reason for engine removal. Category 5 Do this SB when the engine is disassembled and access is available to the necessary sub-assemblies. Do all spare part assemblies. Category 6 Do this SB when the sub-assembly is disassembled and access is available to necessary part. Category 7 Do this SB when the supply of superseded parts is fully used. Category 8 Do this SB if the operator thinks the change is necessary because of what he knows of the parts history. Category 9 Spare parts information only. Old and new parts are directly interchangeable and operators can mix old and new parts. Category 10 For information purposes only. Category CSU Used to evaluate new parts before final introduction in commercial service. Operators who participate should include this SB at the next maintenance or overhaul of the engine.
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INTRODUCTION XIX
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INTRODUCTION XX
ENGINE OVERVIEW
ENGINE OVERVIEW
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ENGINE OVERVIEW 1.1
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PT6A-61 RIGHT FRONT VIEW
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ENGINE OVERVIEW 1.2
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PT6A-64 LEFT FRONT VIEW
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ENGINE OVERVIEW 1.3
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PT6A-60 RIGHT FRONT VIEW
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ENGINE OVERVIEW 1.4
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PT6A-67 LEFT VIEW
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ENGINE OVERVIEW 1.5
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MAJOR ASSEMBLIES AND FLANGES (POWER SECTION MODULE)
B
C
A
EXHAUST DUCT
POWER TURBINE HOUSING
D
POWER TURBINE SHAFT HOUSING
REDUCTION GEARBOX BUS BAR
POWER SECTION
PT6A-60 SERIES
2ND STAGE POWER TURBINE
2ND STAGE VANE RING
TRAINING USE ONLY
1ST STAGE VANE RING 1ST STAGE POWER TURBINE
ENGINE OVERVIEW 1.6
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
MAJOR ASSEMBLIES & FLANGES (GAS GENERATOR MODULE)
G
F C E
DIAPHRAGM COMPRESSOR ASSEMBLY
INLET CASE
GAS GENERATOR CASE COMPRESSOR TURBINE
PT6A-60 SERIES
COMPRESSOR TURBINE VANE RING
COMBUSTION CHAMBER
ACCESSORY GEARBOX COVER
GAS GENERATOR SECTION
TRAINING USE ONLY
ENGINE OVERVIEW 1.7
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FEATURES Modules: - Gas Generator - Power Section
Reduction Gearbox: - 2 stage planetary reduction - Built-in hydro-mechanical torque measurement system. - Reduce the power turbine speed to a speed suitable for propeller operation.
Main Components: Accessory Gearbox: - Driven by the compressor - Provide drives for engine and aircraft accessories Compressor: - 3 or 4 axial stages plus 1 centrifugal impeller. - Provides the necessary air mass flow at the required pressure to sustain combustion and cool hot section components. Combustion Chamber: - Annular type - Reverse flow (shortens engine) - Provides an area for combustion of the air-fuel mixture Compressor Turbine: - Single stage (CCW rotation) - Recuperate power to drive the compressor
Engine Control System: - Variable speed propeller - Reverse thrust capability - Hydro-pneumatic fuel control unit - Fuel control with manual override * - Reserve power capability * - Two or Three lever power management * - Torque limiting device * * Applicable to certain models only. References: Rated power................................. 700 to 1650 SHP Max. air mass flow ....................... 10.22 to 11.21 lbs./sec Max. compressor P/R................... 9:1 to 12:1 Specific fuel consumption ............ .509 to .680 LB/ESHP/hr
Power Turbines: - 2 stage turbine (CW rotation) - Independent from the compressor turbine (free turbine) - Extract energy to turn the propeller
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.8
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NOTES
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.9
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GENERAL TURBOPROP OPERATION The PT6 is a lightweight turbine engine driving a propeller via a two-stage reduction gearbox. Two major rotating assemblies compose the heart of the engine. The first is the compressor and the compressor turbine (compressor section) and secondly, the two power turbines and the power turbine shaft (power section). The two rotors are not connected and rotate at different speeds and in opposite directions. This design is referred to as a "Free Turbine Engine” and has certain advantages: -
The hot expanding gases accelerate through the compressor turbine vane ring and cause the compressor turbine to rotate (which rotates the compressor (approx. 39,000 rpm)). The expanding gases travel across the 1st and 2nd stage power turbines which provides rotational energy to drive the propeller shaft. The reduction gearbox reduces the power turbine speed (30,000 rpm approx.) to one suitable for propeller operation (1700/2000 rpm). Gases leaving the power turbines are expelled to the atmosphere by the exhaust duct.
Np independent of Ng. Lower Starter cranking torque Modular design concept On-wing maintenance (Hot Section Inspection.)
Engine shutdown is accomplished by shutting off fuel going to the combustion chamber.
The compressor draws air into the engine via an annular plenum chamber (inlet case), air pressure increases across 3 or 4 axial stages and one centrifugal stage and is then directed to the combustion chamber.
An integral oil tank located in the rear section of the inlet case and the accessory gearbox provides oil to bearings and other various systems, such as propeller and torque systems.
Air enters the combustion chamber via small holes. At the correct compressor speed, fuel is introduced into the combustion chamber via 14 fuel nozzles. Two spark igniters located in the combustion chamber ignite the mixture. The hot gases generated by the combustion are then directed to the turbine area.
A Woodward Governor Co. fuel control unit mounted on the accessory gearbox regulates fuel flow to the fuel nozzles in response to power requirements and flight conditions.
At this point, ignition is turned off since a continuous flame now exists in the combustion chamber.
PT6A-60 SERIES
The propeller governor mounted on the reduction gearbox, controls the speed of the propeller by varying blade angle, depending on power requirements, pilot speed selection and flight conditions.
TRAINING USE ONLY
ENGINE OVERVIEW 1.10
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
TURBOPROP ENGINE
COMPRESSOR TURBINE 2 ND STAGE REDUCTION GEAR
1 ST STAGE REDUCTION GEAR
POWER TURBINES
ACCESSORY GEARBOX
COMPRESSOR
PROPELLER SHAFT
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.11
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
MAIN ENGINE BEARINGS Function: To support major rotating assemblies and minimize friction. Ball Bearings: Support axial and radial loads. Roller Bearings: Support radial load only and allows for thermal expansion. Rotating Assemblies And Their Supporting Bearings:
Propeller Shaft
Power Turbine
Compressor
No 5: roller
No 3: roller
No 1: ball
No 6: ball
No 4: ball
No 2: roller
Operation: - The ball bearings withstand the following thrusts: - No. 1 bearing: Compressor thrust (rearward) - No. 4 bearing: Power turbine thrust (forward) - No. 6 bearing: Propeller thrust (forward) - Bearing nos. 2, 3, 5 and 7 are roller bearings - They support radial loading and permit axial rotor movement caused by thermal expansion - Bearings are pressure lubricated and cavities are drained by scavenge pumps - No. 1 bearing is gravity drained Maintenance: - None at field level - Inspect oil filter, chip detector - Keep oil pressure within tolerances
No 7: roller Note: Smaller Reduction Gearboxes (PT6A-52/-60/-61/-64 and -66) do not require a No. 7 bearing.
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.12
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BEARINGS
7
6
5
A-60 A-65 A-67
A-52 A-61 A-64 A-66
6
PT6A-60 SERIES
5
4
3
TRAINING USE ONLY
2
1 ENGINE OVERVIEW 1.13
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
STATIONS
7
6
5
4
3
2.5
1
2
1 - AIR INTAKE 2 - COMPRESSOR INLET 2.5 - COMPRESSOR INTERSTAGE 3 - COMPRESSOR DISCHARGE PRESSURE 4 - COMPRESSOR TURBINE INLET 5 - INTERTURBINE 6 - TURBINE EXHAUST 7 - EXHAUST OUTLET
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.14
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
STATIONS PRESS PSIA
TEMP C O
1100 150 140
1000 900
130 120 110 100 90 80 70 60 50 40 30 20 10 0
800 700 600 500 400 300 200 100
1
2
P2.5
P3
NOTE: PRESSURES AND TEMPERATURES LISTED ARE TAKEN AT TAKEOFF POWER, STANDARD DAY FOR A PT6A-65 ENGINE
PT6A-60 SERIES
T4
T5
6
7 TEMPERATURE PRESSURE
TRAINING USE ONLY
ENGINE OVERVIEW 1.15
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ENGINE EXTERNAL COMPONENTS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.
Reversing Cable T5 Harness T1 Trim Resistor (Trim Stick) Decal Patents Designation Cam Box (Reversing) Oil Return From Airframe Cooler Overboard Breather Discharge Oil Dipstick - (Electrical A-67B) Starter/Generator Pad Fuel Control Unit Oil To Airframe Cooler Fuel Pump Oil To Fuel Heater Oil Pressure Tapping P3 Air Filter Oil Filter Cover P3 Air Delivery Tube To Fuel Control Unit Bleed Valve Main Oil Pressure Line Propeller Tach-Generator Pad Data Plate Gas-Generator (Engine) Plate Instructions, Gas Generator
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.16
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
EXTERNAL COMPONENTS
5
1
2
3
4
6 8
7
9 20
10
19 18 21 22 11
16
15 12
PT6A-60 SERIES
17
13
14
TRAINING USE ONLY
ENGINE OVERVIEW 1.17
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
ENGINE EXTERNAL COMPONENTS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.
Inlet Screen P2.5 Cabin Bleed Fireseal - Front Fuel Nozzle Adapter Py Air Line Data Plate - Power Section Propeller Governor (CSU) Propeller Shaft Propeller Overspeed Governor Pad Torque Oil Pressure Port Chip Detector Igniter Plug Engine Mount Pad P3 Cabin Bleed Port Oil Scavenge Tubes Ignition Cables Exciter Box Wash Spray Ring Oil Level Sightglass Rear Fireseal Oil From Airframe Cooler
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.18
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
EXTERNAL COMPONENTS
3
5
7 6
2
4
1
21
8 20 19 18
17
16 14 9
15
10 12
13
11
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.19
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BLANK PAGE
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE OVERVIEW 1.20
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COMPRESSOR SECTION
COMPRESSOR SECTION
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.1
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COMPRESSOR SECTION Function: - Supplies the required mass of air at the right pressure to the combustion chamber and all the supporting systems - Transmits the rotational energy from the compressor turbine to drive the accessories mounted on the accessory gearbox
Subjects Covered: - Inertial separator (airframe) - Inlet case - Compressor assembly - Bleed valve - Pre-swirl system (jet flap piccolo inlet) - Gas generator case - Cold section cleaning
Compressor Air Is Used For The Following: - Sustain combustion in order to produce the energy required to drive the compressor and the power section (propeller) - Provide cooling air for hot section components - Provide air to seal bearing cavities - Assist in the operation of the fuel control unit - Controls bleed valve operation - Provides heating and pressurization for cabin use - De-ice various airframe components
Operation: The compressor draws air into the engine and compresses it before delivery to the combustion chamber area.
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.2
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR SECTION
BLEED VALVE
INLET CASE
COMPRESSOR
GAS GENERATOR
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.3
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
INERTIAL SEPARATOR (AIRFRAME) Function: Protects the engine from ingesting foreign objects such as stones, ice, sand, snow, rain, etc.
Operation:
When carrying-out a performance check, always assure that the inertial separator doors are in the CLOSED position. Inertial separator doors left in the open position will cause an increase in Ng, ITT and Wf which could be interpreted as a deteriorated compressor.
Deployment of the inertial separator to the bypass (icing) position forces air in the nacelle to execute a sharp turn before entering the engine. Water droplets, ice crystals or snow, because of their inertia, tend to maintain their original high velocity path and are discharged overboard through the separator bypass duct.
Note: The inertial separator is an airframe-supplied item. Not using the inertial separator in icing conditions could result in costly damage to the compressor blades. Ensure separator operates freely. Erratic movement of the separator vane may cause engine parameter fluctuation. For specific maintenance action, refer to the Airframe Maintenance Manual.
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.4
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
INERTIAL SEPARATOR (TYPICAL)
BYPASS (ICING) POSITION
NORMAL POSITION
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.5
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR INLET CASE Function: - Directs air into the compressor - Support no. 1 bearing - Forms the oil tank - Piccolo holes in hollow struts generate pre-swirl - Sight glass on left side of case allows for quick oil level check (not on A-60/61/65) - Inlet screen (1/4 inch mesh) prevents objects from entering the compressor
Maintenance: - Inspect inlet screen for damage and cleanliness. Wire mesh damage is not acceptable - Inspect inlet screen rubber sealing rims for damage - Inspect inlet case for cracks in the strut area - Cracks are not acceptable on Inlet Case
Construction: - One piece magnesium casting - External surfaces painted with epoxy paint
Operation: The annular configuration of the PT6 inlet case facilitates the protection against Foreign Object Damage (FOD). Because the compressor rotor intake is not in line with the flight path, the incoming air makes a sharp turn before entering the inlet case. This configuration is combined with the inertial separator for maximum protection against FOD. Piccolo holes in the inlet case strut change the direction of incoming air at the face of the compressor rotor. Inlet case strut anti-icing is provided by heat conduction from the oil contained in the tank.
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.6
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
INLET CASE
OIL TANK VENT AND PRESSURIZING VALVE
FOR WAR D
OIL RETURN FROM COOLER PICOLLO HOLES OIL TO AGB
OIL FILTER HOUSING LOCATION
INLET SCREEN
OIL FROM THERMOSTATIC AND BYPASS VALVE
AIR INLET OIL LEVEL SIGHT GLASS NO.1 BEARING SCAVENGE
PT6A-60 SERIES
OIL TANK DRAIN OIL TANK
TRAINING USE ONLY
NO.2 BEARING SCAVENGE RETURN
COMPRESSOR SECTION 2.7
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COMPRESSOR Function: - Provides the combustion chamber with the correct airflow at the required pressure - The number 1 bearing supports the rear end of the compressor - The flexible housing transforms compressor vibrations Construction: A-52/60/61: - Three axial rotors and a centrifugal impeller - Early engines used assembly of disks and blades for all 3 axial stages - SB 13093, introduces integral bladed rotor (IBR) on 1st. stage only A-65’s: - Four axial (blade & hub) rotors and a centrifugal impeller. - SB 13017 Introduces 1st stage IBR. - SB 13140 Introduces 4 stages of IBR’s. A-64. 66 & 67: - Four IBR type axial rotors and a centrifugal impeller Stator vanes are mounted after each axial rotor. Rotating components are made of titanium and are held in place with tie rods that extend through the compressor stages. Maximum compressor speed 39,000 rpm (104%).
PT6A-60 SERIES
Compression Ratios: 52, 60A,61
9.0
64, 65, 66, 67
12.1
Operation: Axial stage accelerates the air, which is then decelerated through divergent stator vanes, thus increasing the air pressure. The same process is repeated throughout all the compressor stages. The dynamic pressure (air velocity) generated by the centrifugal impeller speed is transformed into static pressure by the diffuser pipes divergent shape which reduces the air speed and increases the compressor discharge pressure (P3). Nos. 1 and 2 bearings support the compressor rotor. The IBR root forms the inner gas path profile; the stator vanes form the outer gas path wall. The no. 1 bearing is supported by the compressor inlet case via a flexible housing. Compressor unbalance caused by normal engine wear produces vibrations that are transformed by the number 1 bearing flexible housing, reducing vibrations transmitted to the engine mounts and aircraft. Maintenance: - Check first stage blades for FOD every time the inlet screen is removed - Blending is recommended to prevent cracks from developing on the leading edge of the blades - Refer to the Engine Maintenance Manual for acceptable blade damage and blending limits - Do compressor Wash at regular intervals
TRAINING USE ONLY
COMPRESSOR SECTION 2.8
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR
BLEED VALVE NO. 2 BRG.
CENTRIFUGAL IMPELLER
AXIAL STAGES PICCOLO HOLES NO. 1 BRG. NO. 1 BRG. FLEXIBLE HOUSING
GAS GENERATOR CASE PT6A-60 SERIES
INLET CASE
TRAINING USE ONLY
COMPRESSOR SECTION 2.9
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COMPRESSOR WASH Function: - Remove salt and dirt deposits from the compressor gas path - Promote parts life and reduce potential overhaul costs
Special Procedure: - If isopropyl alcohol or kerosene was used in the cleaning solution perform a dry motoring run before starting the engine to avoid a hot start.
Type Of Washes: - Desalination wash - Performance recovery wash - Ref. M/M 71-00-00
Method: - Motoring wash - Refer to the Engine Maintenance Manual for washing mixtures preparation and procedures
Prior To Washing, Make Sure That: - 40 minutes minimum cooling period - P3 line going to the FCU is removed* - Cabin bleed is off - No power extraction - Follow starter limitations - Ensure removal of exhaust duct drain plug if installed * Not applicable if post SB 13175/14054 (P3 filter bowl drain valve)
PT6A-60 SERIES
After Wash Procedure: - Reconnect P3 line to the FCU
Desalination Wash: - Recommended when operating in a salt laden atmosphere - Use drinking water with low mineral content - De-mineralized water is recommended Performance Recovery Wash: - Recommended every 100 - 200 hr based on the flying environment - Water based detergents are used to remove stubborn dirt deposits which cannot be removed using water only - Solution is injected into the compressor using the wash ring mounted over the inlet screen - At OAT below 2 °C (36 °F), isopropyl alcohol must be added to the water to prevent freezing - Allow 15-20 minute soaking period - Perform two rinse cycles (water)
TRAINING USE ONLY
COMPRESSOR SECTION 2.10
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR WASH COMPRESSOR WASH RING
SHUTOFF VALVE
PRESS. GAGE REGULATED AIR PRESSURE
PRESS. GAGE
CLEANING SOLUTION
SPRAY RING
WATER
SHUTOFF VALVE
SPRAY RING
REGULATED AIR PRESSURE WATER
DESALINATION SYSTEM PT6A-60 SERIES
PERFORMANCE RECOVERY SYSTEM TRAINING USE ONLY
COMPRESSOR SECTION 2.11
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COMPRESSOR BLEED VALVE (64/65/66/67) Function: Prevents compressor stall at low Ng. Construction: - Non-flowing type - A piston slides on a guide pin inside a housing - Seal rings on the piston minimize Px leak - A classified seat controls the closing point (Ng) of the bleed valve
Px pressure depends on the restriction at the outlet of the cavity where it is drawn. This restriction is controlled by the inside diameter of the compressor turbine stator air seal (baffle). SB14117 introduces a classified stator air seal on certain engine models to improve control of Px pressure. Some late A-65 models also incorporate a classified stator air seal. ( SB 13108 & SB 13311 )
Operation:
The surface area on which P2.5 pushes depends on the inside diameter of the bleed valve classified seat. Different classes of seats are available for bleed valve closing point adjustment.
Two forces act on the bleed valve piston. Px air pressure pushes to close the bleed valve and P2.5 air pressure, from the inter-stage compressor area, pushes to open it. Px is derived from P3 air. P3 passes through a restriction when it flows between the no. 2 bearing housing and the no. 2 bearing cover. At low power setting, Px is lower than P2.5 keeping the bleed valve open. In this position, P2.5 air is directed into the plenum chamber and into the inlet case struts.
Maintenance: - Check for evidence of air losses at sealing faces and mating surface - Check valve seat/piston for damage - Check free movement of piston - Bleed valve closing point - Retain classified seat when replacing bleed valve
When the compressor speed increases, Px rises faster than P2.5, thus increasing the pressure acting on top of the piston to gradually close it. The speed (Ng) at which the valve closes is a function of 2 variables. One is the Px pressure and the second is the surface area on which P2.5 air pressure is pushing on the piston.
PT6A-60 SERIES
The piston can fall out of the BOV assembly when the classified seat is removed
TRAINING USE ONLY
COMPRESSOR SECTION 2.12
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR BLEED VALVE (64/65/66/67)
SEAL RING
RETAINING RING DETAIL A
GUIDE PIN
BLEED VALVE COVER
A PX
PX
PISTON SEAL RING
VALVE SEAT RETAINING RING
BLEED VALVE HOUSING
CLASSIFIED VALVE SEAT
SEAL RING PX (P3) PISTON
PT6A-60 SERIES
TRAINING USE ONLY
P2.5
COMPRESSOR SECTION 2.13
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR BLEED VALVE (52/60/61) As Ng increases, P3 rises faster than P2.5, thus increasing the pressure acting on the piston to gradually close it. The speed (Ng) at which the valve closes is a function of the Primary and Convergent Divergent orifice sizes. A larger Primary orifice requires less Ng speed (less P3 pressure) to close the valve.
Function: Prevents compressor stall at low Ng Description: Pressure operated piston sliding on a guide pin. Piston discharges P2.5 to atmosphere at low Ng. speed. A rolling diaphragm mounted on the valve piston prevents leakage between P2.5 and the Px chamber. Construction: - Flowing type - A piston slides on a guide pin inside a housing - A flexible diaphragm seals the piston - Calibrated orifices control the valve closing point (Ng)
Maintenance: - Check for air losses at sealing faces and mating surfaces - Check that piston moves freely - Check seat or piston for damage - Pressure check - Clean orifices Pressure Check:
Operation:
To verify the integrity of the Bleed Valve diaphragm
Two forces act on the bleed valve piston. Modified P3 air (Px) pressure pushes to close the valve and P2.5 air pressure, from the inter-stage compressor area, pushes to open it.
Description: - Remove Bleed valve spring pin - Seal valve seat on a rubber sheet and secure in position - Remove two plugs on Bleed valves and install appropriate equipment as per M/M - Apply required pressure to valve and check that leakage is within limits
P3 air flows through a primary metering orifice and is directed to the top of the piston and to atmosphere via a convergent divergent orifice. The bleed valve closing point occurs, during engine acceleration, when the pressure acting on the valve diaphragm (Px) is sufficient to overcome the compressor inter-stage pressure (P2.5).
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.14
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BLEED VALVE (52/60/61)
CONTROL PRESSURE (Px) AMBIENT PRESSURE (Pa) COVER ROLLING DIAPHRAGM
FINAL ORIFICE
GUIDE PIN SHAFT PISTON
Px
Px
PRIMARY ORIFICE DISCHARGE TO ATMOSPHERE
PISTON DAMPER (SPRING LOADED)
P3
SLEEVE
DELIVERY AIR PASSAGE P3
PISTON SEAT P2.5
P2.5
CLOSED POSITION
PT6A-60 SERIES
OPEN POSITION
TRAINING USE ONLY
COMPRESSOR SECTION 2.15
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PRE-SWIRL SYSTEM Function: - Change the relative angle of attack of the air entering the compressor - Improve surge margin at low compressor speed Description: - Hollow inlet case struts with holes - Piccolo holes on most A-64/67 - Slotted holes combined with swing check valve and orifice A-52/60/61, A65AG,AR - Bleed valve - Bleed valve plenum chamber
Operation: When the bleed valve opens, P2.5 air flows to the plenum chamber and to the inlet case hollow struts. The piccolo holes located on the inlet case struts produce P2.5 air jets that cause swirling of the incoming air before it enters the compressor. The swirl is turning in the same direction of the compressor, which makes it easier to draw in air thus increase compressor performance at low Ng. Swing Check Valve: Pre-SB13016 A-65 engines use an orifice and a swing check valve to relieve excess P2.5 air pressure when the compressor bleed valve opens. The swing check valve is on the left-hand side of the gas generator on A-65's, or on top of the bleed valve for A-52/60/61's. The swing check valve prevents air from entering the plenum chamber at high power after the bleed valve has closed. Inlet case with Piccolo holes can handle all the airflow without a swing check valve. Maintenance: - Check for proper operation of the bleed valve - Proper installation/sealing of the bleed valve
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.16
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PRE-SWIRL SYSTEM (PICCOLO HOLES)
INLET SCREEN
INLET AIR
P 2.5 INTERSTAGE AIR PICCOLO HOLES
NO. 1 BEARING
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.17
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NOTES
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.18
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PRE-SWIRL SYSTEM (52/60/61) (SLOTTED STRUTS) CASE HOLLOW STRUT TANGENTIAL FLOW (JET FLAP) INLET SCREEN
SWING CHECK VALVE
AIR INLET
A65’s P 2.5 INTER-STAGE AIR COMPRESSOR BLEED VALVE
BLEED AIR CASE ASSEMBLY P 2.5
P 2.5 FIRST - STAGE COMPRESSOR BLADE
P 2.5 NO. 1 BRG. (REF)
GAS GENERATOR CASE
SWING CHECK VALVE
A52/60/61 PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.19
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BLEED VALVE CLOSING POINT (65/67) Note: If closing point does not fall within the tolerance band, the following adjustments can be made.
Function: To verify at what Ng speed the bleed valve closes.
- Install higher class seat to raise Ng closing point - Install lower class seat to lower Ng closing point - Replace bleed valve if piston does not move freely
Description: Use the pressure pick-up port located on the P2.5 cabin bleed adapter.
Bleed Valve Closing Point (64/66): Operation: - The pick-up tube connects to a flexible hose in a container filled with water - Bubbles form when the bleed valve opens - Stabilize engine at ground idle - Increase Ng until bubbles stop forming - Record Ng speed (closing point) - Ensure closing point falls within tolerance band on MM graph
PT6A-60 SERIES
There is no closing point test for these models.
TRAINING USE ONLY
COMPRESSOR SECTION 2.20
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BLEED VALVE CLOSING POINT CHECK 37.5 96 95.1
GAS GENERATOR SPEED (Ng) %
94
NOTE: OPERATING ABOVE THE BAND IS ACCEPTABLE.
92
90
88
P
N LE
86 85.55
UM
P
S RE
SU
RE
−
ZE
RO
OR
NO
B
B UB
LE
S
RUBBER TUBE
NOTE: OPERATING BELOW THE BAND IS NOT RECOMMENDED, AS THIS MAY RESULT IN ENGINE STALL / SURGE DURING ACCELERATION / DECELERATION.
84.25 84
82 −30
−20
−10
0
10
20
30
40
OUTSIDE AIR TEMPERATURE ( C) o
BUBBLER
PT6A-60 SERIES
TRAINING USE ONLY
WATER
COMPRESSOR SECTION 2.21
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BLEED VALVE CLOSING POINT (52/60A/61) Description:
Closing Point Too HIGH (Ng) ->Install Larger Orifice:
A different closing point test is required for these BOV’s because these engines are ‘flat rated’ so they can make more power at higher altitudes and temperatures. For this reason the BOV is open under most circumstances at low altitude and temperature (on the ground). The closing point is extrapolated in reference to a running condition taken as follows: - Remove P2.5 transfer tube from bleed air case and install adapter using suitable flexible tube. Connect to a digital pressure gauge. - Record Tam in degree °C, and Pam in In. Hg. - Start engine, let Ng stabilize at ground idle. - Slowly increase power until plenum pressure (PP) peaks, then starts falling. - Continue to accelerate engine to max. allowable power Ref. M/M. 71-00-00. - Let engine stabilize for 2 minutes, record Ng and PP - Shut down engine. - Calculate normalized Gas Generator speed and normalized plenum pressure as per M/M. 71-00-00 (Adjustment/Test) to determine the closing point as per the chart in the MM. - If closing point is above or below acceptable range replace the primary metering plug with next higher or lower class as required.
PT6A-60 SERIES
If plotted point is above acceptable range with existing class of metering plug, and falls below acceptable range with next higher class from existing plug, the Final Orifice (convergent/divergent) must be enlarged. Refer to M/M section 71-00-00 Adjustment/ Test
TRAINING USE ONLY
COMPRESSOR SECTION 2.22
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BLEED VALVE CLOSING POINT CHECK (52/60/61)
CABIN BLEED AIR TRANSFER TUBE BOSS
DIGITAL PRESSURE GAGE
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.23
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
GAS GENERATOR CASE Function:
Operation:
Houses and supports various engine components such as #2 brg, compressor assembly, engine mounts, diffuser pipes.
The gas generator case houses the components necessary for the compression of air and combustion of the fuel/air mixture. The gas generator case contains P3 air pressure.
The diffuser pipes change the high velocity (2000ft/sec) low pressure into low velocity (200ft/sec) and high pressure. They also turn the air flow 90° to direct the air to the Combustion Chamber.
Tubes for oil pressure and scavenge to the number 2 bearing as well as tapping for P3 air for the operation of the bleed valve and fuel control unit are provided inside the gas generator case.
Description: - Welded assembly of steel alloy machined parts and sheet metal - Diffused aluminized coating - 21 brazed diffuser pipes - Support for the compressor stator parts - Support for the no. 2 bearing - 14 bosses for fuel nozzles - 2 bosses for igniter plugs - 2 bosses for drain valves - 1 boss for P3 air (to FCU) - 1 P2.5 bleed port - 2 P3 bleed port (A-60/61/65 one) - Provision for 6 engine mounts (A-60/61/65 four)
Two P3 operated drain valves located at the six o'clock position ensures fuel does not remain in the case after engine shutdown.
PT6A-60 SERIES
Maintenance: - Inspect for cracks and signs of P3 leaks. - Inspect engine mount threaded holes. - Inspect diffuser pipes for cracks etc. Note: The A67B & D models have studs instead of bolts to secure the nozzles
TRAINING USE ONLY
COMPRESSOR SECTION 2.24
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
GAS GENERATOR CASE / DIFFUSER AIR PRESSURE TUBE TO BLEED VALVE FLANGE "C"
DIFFUSER PIPE
NO. 2 BEARING. PRESSURE OIL TUBE P3 PRESSURE TUBE TO FUEL CONTROL
NO. 2 BEARING SCAVENGE OIL TUBE STRAIGHTENING VANE
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.25
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COLD SECTION TROUBLESHOOTING Problem
Symptoms At Constant Power
Action Required
Ng
T5
Wf
Restricted inlet screen
up
up
up
Clean and/or remove obstruction
Dirty compressor
up
up
up
Perform compressor wash /revise schedule
Damaged compressor blades
up
up
up
Blend blades as per Engine Maintenance Manual. Return to an approved overhaul facility if damage is beyond limit.
Bleed valve stuck open or closing at too high Ng
up
up
up
Ensure P3 is not leaking between bleed valve and gas generator case. Replace bleed valve.
P3 leaks
same
up
up
Check for external leaks on gas generator. Verify sealing surfaces in Hot section at next HSI. Check engine bleed system.
Excessive loading of starter generator or other AGB mounted accessories.
down
up
up
Replace faulty starter
Bleed valve closes too soon
Compressor stalls during acceleration at altitude
Replace faulty BOV. Re-check closing point.
Bleed valve stuck closed
Compressor stalls
Replace bleed valve
Note: Generally, compressor section problems cause Ng, T5 and Wf to increase. However, the above list of possible problems includes some that will make the engine react differently.
PT6A-60 SERIES
TRAINING USE ONLY
COMPRESSOR SECTION 2.26
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMBUSTION & TURBINE
COMBUSTION & TURBINE
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.1
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION Description: Produce and extract energy from the hot expanding gases to drive the compressor turbine, compressor and AGB accessories. At the same time, drive the power turbines / propeller to provide thrust for the aircraft.
Components: - Combustion chamber - Compressor turbine vane ring - Compressor turbine - Power turbine housing - Power turbine vane rings - Power turbines - Exhaust duct
Operation: The hot section of the engine is comprised of components down stream of the compressor. Hot expanding gases leaving the combustion chamber are directed towards the compressor turbine blades by the compressor turbine vane ring and drive the compressor. Gases then travel across the 1st stage power turbine vane ring and drive the 1st stage power turbine (and again across the 2nd stages). Turbine rotation is transmitted to the propeller via the power turbine shaft and the reduction gearbox. Gases leaving the power turbine are expelled to the atmosphere through the exhaust duct. The exhaust gases add some ‘jet thrust’ as a result of the airframe exhaust stubs. PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.2
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION AREA
POWER TURBINES
EXHAUST CASE
SEALING SHROUD SEGMENT RING COMPRESSOR HOUSING TURBINE
COMPRESSOR TURBINE VANE RING SHROUD LOCK SEGMENTS PLATE
C.T. BAFFLE
PT6A-60 SERIES
POWER TURBINE STATOR HOUSING
POWER TURBINE VANE RINGS
NO. 2 BRG COVER
TRAINING USE ONLY
NO. 2 BRG COVER FLANGE
COMBUSTION CHAMBER
SMALL EXIT DUCT
COMBUSTION & TURBINE 3.3
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMBUSTION CHAMBER LINER & SMALL EXIT DUCT Function: Provide an area for the combustion of fuel/air mixture and form an envelope that changes the direction of the gas flow 180°.
Construction: - Annular, reverse flow type combustion chamber - Made of nickel alloy (Inconel) sheet metal - Ceramic coating on inner walls create a thermal barrier - 14 fuel nozzle bosses - 2 spark igniter bosses - Cooling rings protect the combustion chamber walls from the flame
Operation: P3 air enters the combustion chamber through holes in the inner and outer liners. The shape, size and location of these holes provide the correct fuel/air ratio for all operating conditions.
PT6A-60 SERIES
The combustion chamber forms an envelope that turns the gas 180°. This configuration permits location of the turbines closer to the compressor and within the combustion chamber area, thus making the engine shorter and lighter. Cooling rings direct P3 air into the combustion chamber, close to the walls, to form a flame barrier. Maintenance: - Replace the liners as a set. - Check the cooling ring gaps as per MM. - Inspect for cracks, burning, buckling repair as per MM.
Troubleshooting: Intermittent puffs of black smoke indicate carbon build-up in the C.C. The fix is to incorporate a liner with more cooling holes (SB13177/14055) or replace the existing liners with a TDF* liner (SB 14048). * Thermal
TRAINING USE ONLY
Distribution Factor
COMBUSTION & TURBINE 3.4
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMBUSTION CHAMBER AND SMALL EXIT DUCT
FUEL NOZZLE ADAPTER BOSSES
COOLING RINGS
LOUVERED COOLING RING
OUTER LINER
OUTER LINER INNER LINER
COOLING RING
PT6A-60 SERIES
SMALL EXIT DUCT
INNER LINER SMALL EXIT DUCT
TRAINING USE ONLY
SPARK IGNITER BOSS
COMBUSTION & TURBINE 3.5
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR TURBINE VANE RING Vane Ring: - Directs and accelerates gases to the compressor turbine at the optimum angle and speed. - Convergent vanes change static pressure into velocity - The lug to slot fit determines the radial location of the shroud housing and is important for tip clearance control Effect Of Vane Area (Class) On T5 And Ng At Constant Power:
Increase Area
Ng ↓
T5 ↑
Decrease Area
Ng ↑
T5 ↓
Shroud Housing: - Supports shroud segments and inter-stage sealing ring - Slots in the shroud housing match with corresponding lugs on the vane ring to prevent shroud housing rotation Shroud Segments: - Correct class selection and grinding of shroud segments provide adequate blade tip clearance and minimize gas leakage. (10 or 20 segments) - Thickness is classified to fit different compressor turbine outside diameter
PT6A-60 SERIES
Operation: The compressor turbine vane ring receives hot gases from the combustion chamber. The vane airfoil arrangement converges the air towards the exit, accelerating and changing its direction simultaneously. Vane ring classes determine the sum of the area in square inches, of all the openings between the vane trailing edges. At assembly, the proper class of vane is selected to ensure that NG and T5 will be within specified limits. A lower vane ring class (smaller area) accelerates the air therefore increases the speed of the compressor turbine and compressor (Ng). A higher Ng speed provides more air to the engine, increasing cooling and lowering T5. The compressor turbine vane ring is subject to very high temperatures. Vane airfoils are cooled with P3 air. After cooling, air is ejected in the gas path at the vane trailing edge. Shroud segments come in different classes (thickness) to fit different compressor turbine diameters this maintains the gap between the compressor turbine blades and the segments (tip clearance) within specified limits. Replacement: Replace with same area as original or within ±0.03 sq.in. of the original class from the last test. (Ref. SIL PT6A-032)
TRAINING USE ONLY
COMBUSTION & TURBINE 3.6
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR TURBINE VANE RING (52/60/61) COMPRESSIBLE SEALS (SB13168)
INTERSTAGE SEAL RINGS
P3 AIR
OUTER LINER
VANE RING
TIP CLEARANCE
SMALL EXIT DUCT
SHROUD HOUSING P3 AIR P3
SHROUD SEGMENT
LOCK PLATE
P3
COMPRESSOR TURBINE
NO.2 BEARING COVER
P3
POST-SB 13181
PRE-SB 13181 PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.7
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COMPRESSOR TURBINE VANE RING (64, 66, 67A, AG, AF, R)
SHROUD HOUSING INTERSTAGE SEALING RINGS SMALL EXIT DUCT
P3 AIR TIP CLEARANCE VANE RING P3 AIR
SHROUD SEGMENTS COMPRESSOR TURBINE
PT6A-60 SERIES
P3 P3
TRAINING USE ONLY
LOCK PLATE
COMBUSTION & TURBINE 3.8
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR TURBINE VANE RING (66B, 66D, 67B, 67D, 67F and 67P)
COMPRESSIBLE SEALS INTERSTAGE SEALING RINGS TIP CLEARANCE
SMALL EXIT DUCT
P3 AIR
P3 AIR
VANE RING
SEAL RING
P3 AIR P3 AIR
COMPRESSOR TURBINE P3 AIR
LOCK PLATE NO.2 BEARING COVER
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.9
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR TURBINE Function: Extract energy from the hot gases to turn the compressor rotor unit.
Description: - Turbine disk is machined from a nickel alloy. - Blades are cast of a nickel-based alloy and coated with a sacrificial coating for protection against sulphidation. - Fir-tree serration’s support turbine blades and allow for thermal expansion differences between the blades and the disk - Rivets lock the blades onto the disk - A master spline on the disk ensures reinstallation of the compressor turbine in its initial position - PT6A-64/67 blade tip is hollow (pocketed), to reduce weight and centrifugal pull
At maximum speed, the compressor rotor turns at approximately 39,000 rpm (104%), with each blade pulling on the disk with a force of approximately one ton (2000 lbs.). The turbine is individually balanced on two planes with detail weights. This feature allows for turbine replacement in the field. The PT6A-64/66/67 has detail weights plus trim weights to match the disk to the compressor rotor.
Engine Type
# Of Blades
A52/60/61/65
59
A64 pre SB14118 A66/67R,A,AF pre SB14061
52
A64 post SB14118 A66/67R,A,AF post SB 14061 A66B/D, A67B, D, F, P
43
Operation: Expanding gases, accelerated through the vane ring hit the turbine blades. The energy available in the gases is converted into rotational movement to drive the compressor and the engine accessories. Nearly two thirds of all the energy available from the products of combustion is needed to drive the compressor and the accessories. The remaining one third is used to drive the power turbines.
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.10
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR TURBINE
MASTER SPLINE
DETAIL WEIGHT
CUP WASHER RETAINING BOLT PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.11
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR TURBINE TRIM BALANCING (64, 66, 67) Function:
Example:
A residual unbalance remains once the CT is mated with the compressor assembly. Adding TRIM weights minimizes vibration and maintains original compressor rotor balance during field replacement of the compressor turbine.
1st weight -- B 05 L --
Description: - Detail Balancing (PWC approved facilities only) - Initial balancing of the compressor turbine using detail weights on the two balancing planes - Trim Balancing - After initial detail balancing, the compressor turbine is re-balanced with the compressor assembly using trim weights on the same two balancing planes.
L
B 05
Denotes trim weight class (A,B, C, D, E and G) Number from 01 to 40 denotes position of first rivet retaining trim weight from number 1 in direction of J arrow. Denotes weight offset in relation to first hole occupied by weight retaining rivet from number 1 in direction of arrow. - H Heavy offset - L Light offset - N No offset (weight symmetrical)
Note: - The data plate indicate the location of the trim weights - Trim weights are always installed in pairs facing one another on the two balancing planes. - Detail weights are installed by approved facilities only - Trim weights can be installed by the operator - An Overhaul Shop or Service Center can install the trim weights when requested by the operator
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.12
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR TURBINE TRIM BALANCE WEIGHTS
1 2 3 C/T DISK REAR FACE 4 5 6 7 8 9 10
#1 ALIGNED WITH MASTER SPLINE
PLANE A
PLANE B
REAR FACE
FRONT FACE
MANUFACTURED HEADS ON INSIDE OF RIM, BOTH FACES
8
7
6
5
2 1 4 3
C/T DISK FRONT FACE LIGHT OFFSET HEAVY OFFSET
9 10 DATA PLATE PERFORMANCE REFERENCE DATA NG AT 1137 35050 √θ
SHP
δ √θ
THIRD WEIGHT
O
23 OHMS C ITT TRIM 90.2 COMPRESSOR TURBINE TRIM WEIGHTS B 05 L B 08 H G 10 N N/R ENG. BUILD SPEC.
G 10 N
T.C.
DENOTES TRIM WEIGHT CLASS A CLASS 1 C CLASS 3 E CLASS 5 B CLASS 2 D CLASS 4 G NO WEIGHT, RIVET ONLY A
B CL1
D
PT6A-60 SERIES
DENOTES WEIGHT OFFSET IN RELATION TO FIRST HOLE OCCUPIED BY WEIGHT RETAINING RIVET FROM NUMBER 1 IN DIRECTION OF ARROW
H. HEAVY OFFSET L. LIGHT OFFSET N. NO OFFSET (WEIGHT SYMMETRICAL)
C CL3
CL2 G
E CL4
NUMBER FROM 01 TO 40 DENOTES POSITION OF FIRST RIVET RETAINING TRIM WEIGHT FROM NUMBER 1 IN DIRECTION OF ARROW.
CL5
TRAINING USE ONLY
COMBUSTION & TURBINE 3.13
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
ALTERNATE TRIM WEIGHTS (64/66/67) Function: Allows the trim balancing to perform even when the trim weights location as per the data plate is occupied by detail balancing weights.
Description: A table in the maintenance manual provides a choice of alternative location to install the trim weights away from the position marked on the reference data plate when this position is occupied by detail balancing weights. The trim weight is replaced by a pair of weights that are installed on each side and equidistant from original trim weight location (ref. data plate)
Starting from hole no. 4 counter clockwise and from hole no. 7 clockwise (the weights are installed at holes no. 39 and 40 on one side and holes no. 11 and 12 in the other). Alternatively, 2 class # 1 weights can be installed 6 holes away or 2 class # 4 weights can be installed 8 holes away. For cases where class 2 or class 4 weights must be installed as alternate trim weights; try to maintain symmetry by installing one weight with a light offset and the other with a heavy offset.
Example: On the turbine illustrated below there is a detail weight at the positions 5 and 6 so the trim weight B 05 L marked on the data plate cannot be installed (interference at hole no. 5). According to the table, we can replace a “B” type weight (class 2) by installing two class # 1 (‘A’) weights, 5 holes away on each side of the detail weight.
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.14
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
ALTERNATE TRIM WEIGHTS
NOTE: WHEN A NEW DETAIL WEIGHT OCCUPIES A TRIM WEIGHT ORIGINAL LOCATION (REF. DATA PLATE), ALTERNATIVE TRIM WEIGHTS MUST BE USED IN PAIRS ONE EACH SIDE OF AND EQUIDISTANT FROM ORIGINAL TRIM WEIGHT LOCATION (REF. DATA PLATE).
TRIM WEIGHT TABLE
ORIGINAL POSITION OF TRIM WEIGHT (REF. DATA PLATE), NOW OCCUPIED BY NEW DETAIL WEIGHT. C/T DISK ASSEMBLY BALANCING RIM
37
38
39
40
2 1
3
4
35
NUMBER OF HOLES EACH SIDE OF ORIGINAL TRIM WEIGHT LOCATION
5
5 HOLES
36
6 7 8
34 33
5 HOLES
32
G C D E A B CLASS CLASS CLASS CLASS CLASS SINGLE RIVET 3 4 5 1 2
TRIM WEIGHT CLASS FROM DATA PLATE
9
1
CL1
2
CL1
3
CL1
4
CL1
CL2
CL1
CL1
CL2 CL3
5 6
CL1
CL1
CL2
7
CL1
CL3
CL4
8
CL3
CL4
CL5
SINGLE RIVET
10 11 12
ALTERNATIVE TRIM WEIGHT LOCATION DETERMINED USING TRIM WEIGHT TABLE
DATA PLATE
13
PERFORMANCE REFERENCE DATA NG AT 1137 35050 √θ
CT DISK ASSEMBLY TRIM WEIGHTS
SHP
δ √θ
OHMS CO 23 ITT TRIM 90.2 COMPRESSOR TURBINE TRIM WEIGHTS B 05 L
B 08 H
G 10 N
ENG. BUILD SPEC.
PT6A-60 SERIES
TRAINING USE ONLY
N/R T.C.
COMBUSTION & TURBINE 3.15
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
POWER TURBINE VANE RINGS Function: - Direct gases to the first and second stage power turbines at the optimum speed and angle - Change static pressure into velocity First Stage: - Riveted centre baffle directs air for cooling onto the Compressor turbine disk and the power turbines. - Exit area of the vane ring is classified. - Keep with the Gas Generator as a matched set. Second Stage: - Inner section supports an abradable seal. - Both vane rings are supported by the Power Turbine Housing. - A lug to slot arrangement centralizes and prevents rotation of the two vane rings. - Not classified
Effect Of Vane Ring Class Change At Constant Power:
Increase area
Ng ↑
T5 ↓
Decrease area
Ng ↓
T5 ↑
PT6A-60 SERIES
Operation: Gases leaving the compressor turbine are accelerated through the first and second stage vane rings while causing their respective power turbines to rotate. The first and second stage vane rings are held in place by lugs fitted in the power turbine housing. The riveted inner baffle directs air close to the power and compressor turbine disks for cooling. The selection of different vane areas allows for optimization of Ng vs. T5 during engine test. The second stage vane ring supports an abradable seal that diverts cooling air to the two adjacent faces of the power turbines.
Replacement: Replace within ±0.1 sq.in. of the original area from the last test. (Ref. SIL PT6A-032)
TRAINING USE ONLY
COMBUSTION & TURBINE 3.16
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
POWER TURBINE VANE RINGS P.T. VANE RING FIRST STAGE
T5 PROBE SLOT
OW
FL AIR P.T. VANE RING SECOND STAGE
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.17
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
POWER TURBINES Function:
Operation:
Extract energy from the gases to drive the propeller through the reduction gearbox.
The two power turbines extract the energy necessary to drive the propeller.
Description: - Turbine disks are machined from nickel alloy - Coupled together by a lug to slot arrangement - Fir-tree serration’s in the disks support the blades and allow for thermal expansion differences between the disk and the blades - Rivets lock the blades in place - 2nd stage turbine attaches to the power turbine shaft via splines - Power turbine blades are shrouded at the tip to form a solid rim around blade tips and reduce blade vibration - To allow for thinner, more efficient airfoil that offsets the weight penalty of the shrouded blade tips - To reduce gas leakage at the tip of the blade - No shroud segments, a double knife edge provides sealing at the blade tip
The rotational energy extracted by the power turbine is transmitted to the power turbine shaft through splines on the second stage turbine hub. Removal of the power turbines is permissible at field level to replace the second stage vane ring. Balancing of the power turbines is done with the power turbine shaft and the number 3 and 4 bearings, this is the reason why power turbines are not field replaceable.
Maintenance: - Inspect the 2nd stage PT blades for cracks. SB 14172 Pre SB every 1500 hrs. Post SB every 4000 hrs.
References: Max Nf A-52/60/61 .................................. 30400 rpm Max Nf A-64 ............................................ 30144 rpm Max Nf A-66 ............................................ 30400 rpm Max Nf A-65/67 ....................................... 29930 rpm
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.18
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
POWER TURBINES FIRST STAGE POWER TURBINE SHROUDED BLADES
AIR SEAL
SECOND STAGE POWER TURBINE PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.19
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
TURBINE WASH Function:
Sulphidation:
Remove salt deposits from the turbine section of the engine to minimize sulphidation of the turbine blades.
Sulphidation is a common name for a type of hot corrosion which can affect turbine area components.
Method: Motoring wash with turbine wash nozzle inserted in igniter port. PT6A-67B/D/F/P’s have a dedicated wash port.
Description: The washing medium used is drinkable water. It is recommended that this procedure be carried out when operating in a salt laden atmosphere. It is also recommended to perform the turbine wash in conjunction with compressor wash. It is essential that the compressor section be washed first (refer to compressor section in this manual). Water is injected into the turbine section using a turbine wash nozzle through one igniter port. Ensure that the arrow sign on the tool tang is pointing towards the reduction gearbox. The procedure to perform the turbine wash is identical to the compressor desalination wash. Refer to the Engine Maintenance Manual chapter 71 for more details.
Sulphidation occurs at engine operating temperatures when sodium and sulphur are present. All turbine fuels contain sulphur in sufficient amounts for this chemical reaction to occur. Common sources of sodium are seawater, atmospheric pollutants and volcanic discharge. Sulphidation attacks the CT blades, but it is not uncommon for the CT stator and other non-rotating components to be affected. It can not be detected by performance run data analysis. Stage 1: Initial coating deterioration. Slight roughening of the surface caused by some growth and breakdown of the oxide layer. Mechanical integrity is not affected. Stage 2: Initial corrosion. Surface roughness is more marked as oxide layer breakdown continues. Mechanical integrity is not affected. Stage 3: Advanced corrosion. Oxidation of the base material has penetrated to significant depth, with obvious build-up scale. Mechanical integrity seriously affected. Progression to Stage 4 will accelerate. Stage 4: Severe corrosion. Deep penetration, large blisters are apparent. Failure is likely due to loss of structural material.
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.20
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
TURBINE WASH
SHUTOFF VALVE
1
2
3
4
CLEAN OR DEMINERALIZED WATER PRESSURE GAGE REGULATED AIR / NITROGEN PRESSURE
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.21
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
EXHAUST DUCT & PT SHAFT HOUSING Exhaust Duct: - Direct the exhaust gases to ambient atmosphere with minimum flow restriction - Welded assembly of heat resistant Nickel alloy sheet metal - On the A-67R/A-65AR, the exhaust duct is rotated 30° to suit the airframe installation (Shorts) Power Turbine Stator Housing: - Support the power turbine vane rings, the T5 harness and thermocouples - Interfaces with the gas generator section via a seal ring Insulation Blanket: - Minimizes heat transfer between the hot gases and the reduction gearbox and the power turbine shaft housing Power Turbine Shaft Housing: - Support the power turbine shaft - Forms a cavity for bearing no. 3 and 4 Power Turbine Shaft: - Supported by bearing no. 3 and 4 - Transmits power turbine speed and torque to the reduction gearbox via the power turbine shaft coupling and the reduction gearbox first stage sun gear
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.22
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
EXHAUST DUCT & PT SHAFT HOUSING
PT SHAFT HOUSING
POWER TURBINE SHAFT
NO. 3 BEARING POWER TURBINES POWER TURBINE STATOR HOUSING PT SHAFT HOUSING
FLANGE "B" RGB REAR CASE
PT6A-60 SERIES
INSULATION BLANKET
POWER TURBINE VANE RINGS
NO. 4 BEARING EXHAUST DUCT
TRAINING USE ONLY
COMBUSTION & TURBINE 3.23
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
SEALING OF THE HOT SECTION AREA (52/60/61/64/65/66/67, A, AF, R) Function: Gas sealing in the hot section area is a very important factor affecting hot section life. This section describes the major sealing surfaces in the hot section and their purposes.
Sealing Face
Description
Function
A
Vane ring to small exit duct and shroud housing
Prevent P3 air around the combustion chamber to leak and bypass the vane ring
B
Lock plate to vane ring
Prevent P3 leaks from combustion chamber area to other side of vane ring
C
Power turbine housing to shroud housing seal
Prevent P3 leaks into P5
D
First stage PT vane to second stage PT vane
Prevent leaks around the second stage vane ring
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.24
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION SEALING
B A
D C
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.25
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
SEALING OF THE HOT SECTION AREA (67AG, 67B, D, F, P, T, 66B, 66D) Function: Gas sealing in the hot section area is a very important factor affecting hot section life. This section highlight sealing surfaces in the hot section and their functions.
Sealing Face
Description
Function
A
Lock plate to vane ring
Prevent P3 leaks between combustion chamber and no. 2 bearing cover area.
B
Small exit duct to shroud housing
Prevent P3 leaks between combustion chamber and vane ring top section.
C&D
Vane ring to shroud housing
Forms a chamber for vane ring cooling air.
E
Power turbine housing to shroud housing seal ring
Prevent P3 leaks into P5
F
First stage Power turbine vane to second stage PT vane
Prevent leaks around the second stage vane ring.
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.26
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION SEALING
F
PT6A-60 SERIES
E
D
C
TRAINING USE ONLY
B
A
COMBUSTION & TURBINE 3.27
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION TROUBLESHOOTING
Problem
Symptoms At Constant Power
Action Required
Ng
T5
Wf
Seal ring leak
Same
Up
Up
Reposition or replace seal ring. Verify seal ring groove and replace shroud housing if damaged.
Gas leakage at junction between small exit duct and vane ring
Same
Up
Up
Lap sealing faces. Send parts to an approved shop if required to restore the sealing faces. Replace compressible seals (certain models only)
Burnt CT vane ring (larger throat area)
Down
Up
Up
Replace vane ring
High compressor turbine tip clearance
Down
Up
Up
Replace shroud segments to restore clearance. Send turbine to overhaul facility for reblading if necessary.
Eroded compressor turbine blades
Down
Up
Up
Send assembly to an approved facility for blade replacement.
NOTE: Hot section problems are all characterized by high T5 and Wf. Ng usually goes down or remains constant.
PT6A-60 SERIES
TRAINING USE ONLY
COMBUSTION & TURBINE 3.28
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GEARBOXES
GEARBOXES
PT6A-60 SERIES
TRAINING USE ONLY
REDUCTION GEARBOX 4.1
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REDUCTION GEARBOX Function: Reduce the power turbine speed to a speed suitable for propeller operation. Construction: - Two stage planetary reduction system - Magnesium front and rear housing Reduction Ratios: 60A/65/67
A-52/A61/64/66
1St Stage
5.78:1
5.33:1
2nd Stage
3.04:1
2.83:1
Overall ratio
17.58:1
15.10:1
Max. Np (rpm)
1700
2000
Operation: The PT6 engines use a planetary type reduction gearbox system with two stages of reduction. The first stage consists of a sun gear meshing with three planet gears mounted in a carrier. The three planet gears mesh on the outside with a ring gear splined into the reduction gearbox casing. The first stage gear carrier drives the second stage sun gear through a flexible coupling arrangement. Provision to measure torque is provided by the first stage reduction system.
PT6A-60 SERIES
The second stage reduction system is similar to the first stage but uses five planet gears instead of three. The second stage gear carrier drives the propeller shaft via splines. Reverse rotation on the A-66 is achieved by securing the second stage carrier to the front reduction gear case and allowing the second stage ring gear to rotate. A bevel gear on the propeller shaft provides drive for 3 RGB mounted accessories: 1. Propeller Governor (CSU) 2. Propeller Overspeed Governor (A/F) 3. Np Tacho Generator Maintenance: - Verify chip detector for metal contamination. - Verify reduction gearbox scavenge strainer for metal contamination. - Replace propeller shaft oil seal if leak is evident. - Replace Np Tach-Gen lip seal on RGB accessory drives - Touch-up scratches on prop shaft. - CSU & OSG gaskets - Field repairs are not allowed inside the reduction gearbox.
TRAINING USE ONLY
REDUCTION GEARBOX 4.2
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REDUCTION GEARBOX REAR HOUSING 2ND STAGE
1ST STAGE
FRONT HOUSING
PT6A-60 SERIES
TRAINING USE ONLY
REDUCTION GEARBOX 4.3
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STANDARD ROTATION REDUCTION GEARBOX
SECOND STAGE PLANET GEAR
SECOND STAGE RING GEAR
FIRST STAGE RING GEAR
ACC. DRIVES(3) FIRST STAGE PLANET GEAR
FIRST STAGE SUN GEAR SECOND STAGE SUN GEAR
PT6A-60 SERIES
TRAINING USE ONLY
REDUCTION GEARBOX 4.4
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PT6A-66 REVERSE ROTATION GEARBOX
PT6A-60 SERIES
TRAINING USE ONLY
REDUCTION GEARBOX 4.5
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ACCESSORY GEARBOX Function: Provides drive pads for engine and airframe accessories such as: - Fuel pump and fuel control unit - Starter-generator - Oil pressure and scavenge pumps - Ng tacho-generator - Optional aircraft accessories - Centrifugal breather impeller to separate air from oil in the accessory gearbox
Forms a housing and supports the following: - Oil filler neck - Electric/standard dipstick - Oil filter and housing assembly - Oil pressure pump - Oil pressure regulating valve - Cold oil pressure relief valve
PT6A-60 SERIES
Construction: - Two light alloy casings (diaphragm and rear hsg.) support the drive gears. - The casings are bolted together and then to the inlet case. - The front casing (diaphragm) separates and seals the accessory gearbox from the oil tank
Maintenance: - On condition - Replace accessory drive seals - Replace air/oil separator carbon seal - Replace starter drive gear - Inspect AGB scavenge pump inlet screen
TRAINING USE ONLY
REDUCTION GEARBOX 4.6
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ACCESSORY GEARBOX
FUEL PUMP & FCU GEAR CENTRIFUGAL BREATHER & STARTER GENERATORS GEARS 6250 RPM 11000 RPM
7650 RPM
4200 RPM
OPTIONAL ACCESSORY DRIVES
PRE-SB14112 MAIN OIL PRESSURE PUMP, OIL SCAVENGE PUMP & 12000 TACHO-GENERATOR RPM EXTERNAL OIL SCAVENGE & OPTIONAL DRIVE
PT6A-60 SERIES
POST-SB14112
3800 RPM
TRAINING USE ONLY
REDUCTION GEARBOX 4.7
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PIN LOCK ARRANGEMENT
COMPRESSOR HUB
PIN
A.G.B. COUPLING SHAFT
INSERT SEAL RING
PT6A-60 SERIES
SPRING
SLEEVE
TRAINING USE ONLY
REDUCTION GEARBOX 4.8
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ACCESSORY GEARBOX BALL-LOCK ARRANGEMENT PRE SB13161
FLANGED ROLLER BEARING
ACCESSORY GEARBOX HOUSING ACCESSORY GEARBOX DIAPHRAGM BALL LOCK REAR HUB COMPRESSOR ASSEMBLY
PLUG
OIL TRANSFER TUBE GEARBOX INPUT DRIVESHAFT INLET CASE
PT6A-60 SERIES
TRAINING USE ONLY
PRESSURE PUMP
REDUCTION GEARBOX 4.9
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NOTES
PT6A-60 SERIES
TRAINING USE ONLY
REDUCTION GEARBOX 4.10
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OIL SYSTEM
OIL SYSTEM
PT6A-60 SERIES
TRAINING USE ONLY
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OIL SYSTEM 5.1
OIL SYSTEM Function: - Supplies filtered oil to the engine in order to cool, lubricate and clean various components - Provides oil to the propeller governor to allow propeller pitch and speed control. - Provides oil to the torque measurement system Description: The engine oil system consists of a pressure system, a scavenge system and a breather system. The PT6 lubrication system provides a constant supply of clean oil to the engine bearings, reduction gears, accessory drives, torquemeter and propeller governor. The oil tank is integrated in the engine air inlet casing. The oil lubricates and cools bearings and carries any extraneous matter to the oil filter where it is precluded from further circulation. A chip detector is located on the reduction gearbox to detect metal particles and warn operators of metal contamination. Servicing: - Use approved synthetic oil listed in SB 13001 and 14001. - Check oil level within 15-20 minutes after shut down. - If more than 30 minutes have elapsed before checking oil level, and dipstick shows oil is needed, run engine prior to adding oil. - Oil changes required as specified by the Airframe maintenance manual. - Ensure that oil pressure is within limits (approx. 90-135 PSIG). Check with NG above 72%.
PT6A-60 SERIES
Oil System Flushing: - Flush oil system if new type of oil is to be used - Refer to Engine Maintenance Manual for flushing procedure - Changing from Type II to Type II Third Generation oil can only be done with new or newly overhauled engines Oil Temperature Limits (Typical): Starting:......................................................- 40° C min Take off:......................................................0° C - 110° C Recommend oil temp: ................................74° C - 80° C Note: Refer to engine Maintenance Manual for specific limits. Max Oil Consumption: - 0.3 lb/hr oil consumption - measured over a 10 hour period - (3 lb/10 hr.) (2 lb/10 hr. for A-52/60/61/66)
References: 3 lbs ......................................................... 1.5 U.S. qt Oil tank capacity........................................ 2.5 U.S. gal Oil tank expansion space .......................... 0.7 U.S. gal Oil tank usable quantity............................. 1.5 U.S. gal
TRAINING USE ONLY
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OIL SYSTEM 5.2
OIL SYSTEM (BOTTOM VIEW)
OIL TO AIRFRAME COOLER
OIL PRESSURE LINE
OIL OUT TO COOLER
NO. 2 BEARING
NO. 3 & 4 BEARING
SCAVENGE PRESSURE
PT6A-60 SERIES
RGB & PROPELLER
TRAINING USE ONLY
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OIL SYSTEM 5.3
OIL SYSTEM Pressure System: Oil is drawn from the oil tank through a gear type pump and is delivered to the oil filter and Pressure Regulating Valve. At the filter outlet, pressure oil separates into several paths. The no. 1 bearing and accessory input drive shaft are lubricated with oil directed through cored passages and transfer tubes. The oil pressure transmitter and the oil temperature bulb are mounted on ports located on this internal passage. A single tube located at the bottom right hand side of the engine, delivers oil to lubricate the no. 2, 3 and 4 bearings, the reduction gearbox, front accessories and then to the propeller and torque measurement systems.
The accessory gearbox receives oil from the No. 1, 2, 3 and 4 bearings scavenge systems. From there, the oil is routed to the fuel heater by the AGB scavenge pump. From the outlet of the fuel heater, the oil is directed to the thermostatic bypass valve. Depending on the oil temperature, the thermostatic bypass valve directs the oil to either the oil tank or the airframe oil cooler. The oil coming back from the airframe oil cooler gets back to the tank through an anti-splashing adapter at the top of the tank.
Scavenge System: The scavenge system consist of four gear type pumps assembled in two double elements. Two pumps are located inside the accessory gearbox while the other two are mounted externally at the rear of the accessory gearbox. No. 1 bearing scavenges into the accessory gearbox by gravity. No. 2 bearing scavenge through a tube mounted underneath the engine. At high power a relief valve mounted on the line near the scavenge pumps allows air/oil from the bearing cavity to bleed into the accessory gearbox, preventing flooding of the number 2 bearing cavity.
PT6A-60 SERIES
TRAINING USE ONLY
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OIL SYSTEM 5.4
OIL SYSTEM (REAR)
FUEL HEATER
OIL IN FROM AIRFRAME COOLER THERMOSTATIC BYPASS & CHECK VALVE CENTRIFUGAL BREATHER
TO OIL AIRFRAME COOLER
MAIN OIL FILTER
C P R V
OIL PRES. PUMP
P R V PRESSURE TRANSMITTER TEMP. BULB
SCAVENGE OIL
TANK DRAIN
OIL SUPPLY TO PROPELLER & REDUCTION
PT6A-60 SERIES
TRAINING USE ONLY
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OIL SYSTEM 5.5
OIL SYSTEM (CONT’D) No. 3 and 4 bearing area scavenge into the accessory gearbox via a scavenge tube mounted on the left-hand side of the engine. Oil is scavenged by one of the externally mounted pumps located at the rear of the accessory gearbox. The reduction gearbox and the propeller oil system are scavenged through an external tube located beside the No. 3 and 4 bearing scavenge tube. The oil is pumped by the second externally mounted scavenge pump and goes directly to the airframe oil cooler. Note: The PT6A- 64/66/67/67A/AF/AG/B/D/F/P/R scavenge system differs from the other engines. The No. 2 bearing scavenge pump sends oil directly to the fuel heater and diverter valve instead of sending it to the accessory gearbox. (post SB 14108)
PT6A-60 SERIES
TRAINING USE ONLY
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OIL SYSTEM 5.6
OIL SYSTEM (FRONT)
TORQUE PRESS. TRANSDUCER
PROPELLER GOVERNOR
OIL SUPPLY TO PROPELLER
TORQUEMETER
OIL SUPPLY TO PROPELLER AND REDUCTION
PT6A-60 SERIES
SCAVENGE OIL
TRAINING USE ONLY
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OIL SYSTEM 5.7
OIL PRESSURE REGULATION & FILTRATION Oil Pump: - Gear type - Inlet screen protects the pump
Pressure Regulating Valve: - Maintains engine oil pressure within specified limits (90 - 135 PSI) (100 - 135 PSI for PT6A-52/60/61/64 /66). - When oil pressure increases above the spring tension, the valve moves up, opening a passage to the inlet of the pump, thereby limiting the oil pressure
Cold Oil Pressure Relief Valve: - Controls excessive pressure build up during cold weather starting - When the pressure regulating valve is fully open and oil pressure keeps increasing, the cold oil valve opens to dump more oil back to the pump - The relief valve opens at 160 psid
Filter Check Valve: - Opens at a 15 psid to allow oil flow to the filter. - Prevents static oil transfer from the oil tank to the pressure system and AGB. - Inspection of the oil filter without draining the oil tank
PT6A-60 SERIES
Filter: - 15 micron filter with 40 micron internal screen. - Clean electro-sonically only (post SB 13412 and 14392 are not cleanable). - Inspect every 100 hours. - Discard at 1000 hours
Filter Bypass Valve: - Bypasses oil if the oil filter becomes restricted - Valve opens when pressure inside the oil filter is 24 psi lower than the pump pressure - Allows oil to flow through the secondary filter and to engine lubrication system - At this point, indicated oil pressure is lower than normal (24 psid)
Maintenance: - Service oil tank - Check chip detector for presence of metal - Maintain oil pressure within limits - Inspect and clean oil filter - Replace oil filter at 1000 hr - Replace oil if operated above max oil temperature - Min oil pressure @IDLE : 60 psi
TRAINING USE ONLY
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OIL SYSTEM 5.8
OIL PRESSURE REGULATION & FILTRATION
PRESSURE REGULATING VALVE COLD OIL PRESSURE RELIEF VALVE BLEED ORIFICE FILTER
SECONDARY FILTER
BYPASS VALVE
INLET CASE REF
OIL PUMP
FILTER HOUSING
OIL BY PASS OIL PRESSURE OIL FILTERED PRESSURE OIL
PT6A-60 SERIES
`O`RING
CHECK VALVE
OIL PUMP GEARS
TO PRESSURE SYSTEM
INLET SCREEN
TRAINING USE ONLY
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OIL SYSTEM 5.9
THERMOSTATIC BYPASS & CHECK VALVE Function: Bring oil to normal operating temperature faster during first few minutes of engine operation.
Description: - Mounted on the inlet case - Consists of a housing, a thermostatic valve and a check valve
Operation: Oil coming out from the fuel heater is directed to the thermostatic bypass and check valve. The thermostatic element contracts when the oil is cold. This allows the oil to return to the tank instead of going to the airframe oil cooler. The check valve prevents back flow of the scavenge oil from the reduction gearbox to the tank through the thermostatic bypass valve. As the oil warms-up, the thermostatic element expands to gradually close the bypass valve. It begins to close when the oil temperature reaches approximately 60° C and is fully closed around 72° C. As the bypass valve closes, the oil is forced towards the check valve.
PT6A-60 SERIES
The check valve opens when the oil pressure coming from the fuel heater is higher than the pressure of the scavenge oil from the reduction gearbox by 5 psi. This allows the oil from the fuel heater to mix with the reduction gearbox scavenge oil and go to the airframe before it returns to the tank. If the bypass valve fails to open at low oil temperatures then oil pressure will build up and force the check valve to open. If the check valve can not open, the relief spring of the thermostatic bypass valve bypasses oil from the fuel heater to the tank, even if the expansive material is fully expanded, to prevent over pressurization and over loading of the accessory gearbox scavenge pump. A pressure of 40 to 55 PSID is necessary to overcome the relief spring.
Maintenance: Thermal element can be replaced in the field if defective. Check valve may be lapped in the field.
Troubleshooting: - Oil taking too long to reach normal operating temperature may be caused by faulty thermostatic element - Oil temperature higher than normal may be caused by faulty thermostatic valve and/or check valve stuck closed.
TRAINING USE ONLY
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OIL SYSTEM 5.10
THERMOSTATIC BYPASS & CHECK VALVE
RETURN FROM COOLER EXPANSIVE THERMOSTATIC MATERIAL ELEMENT OIL OUT TO TANK BYPASS VALVE
AGB OIL TANK
RETURN SPRING
OIL FROM AGB SCAVENGE
FCU
RELIEF SPRING
CHECK VALVE
OIL OUT TO AIR FRAME COOLER
SCAVENGE OIL AIR & OIL MIST AIRCRAFT BOOST FUEL PRESSURE
PT6A-60 SERIES
FUEL IN
FUEL OUT
FUEL HEATER
THERMOSTATIC BYPASS
OUT TO COOLER RGB SCAVENGE
TRAINING USE ONLY
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OIL SYSTEM 5.11
OIL SYSTEM TROUBLESHOOTING
Symptoms
Possible Cause And Fix
High Oil Pressure
Check indicating system Adjust/verify pressure regulating valve.
Low Oil Pressure
Clean/replace oil filter Check indicating system Cracked oil pump housing Adjust pressure regulating valve
Oil Pressure Fluctuation
Check oil level Check indicating system Check oil tank pressurizing valve Replace/Clean pressure regulating valve
High Oil Temperature
Check oil temperature indicating system Check airframe oil cooler Check thermostatic bypass and check valve Check scavenge pump inlet for blocage
PT6A-60 SERIES
TRAINING USE ONLY
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OIL SYSTEM 5.12
OIL SYSTEM TROUBLESHOOTING (CONT’D))
Symptoms
Possible Cause And Fix
Excessive Oil Discharged From Overboard Breather
Oil level kept too high. Verify oil filter check valve (static transfer, blown out during start). Check O-rings between oil filter housing and inlet case (static transfer) Verify/replace centrifugal breather carbon seal in accessory gearbox. Check pressure pump drive seal (static transfer blown out during start). Check AGB scavenge pump screen for blockage (flooding of AGB).
Excessive Oil Consumption
All of the above. Check for oil external leaks. Ensure oil is not transferring into AGB & leaking out of Inlet/BOV. Check for traces of oil in the exhaust (#3 brg. lab. seal leaking). Check oil to fuel heater for internal leakage.
Oil Leak From Intake (Oil Transfer To AGB)
Check O-ring and Teflon® ring on oil filter housing. Check oil filter check valve for leakage. Main oil pump lip seal. Check for broken O-rings in AGB.
Oil Pressure Follows Power Lever
Check Main Oil Pump Housing for correct assembly torque or cracks.
PT6A-60 SERIES
TRAINING USE ONLY
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OIL SYSTEM 5.13
NOTES
PT6A-60 SERIES
TRAINING USE ONLY
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OIL SYSTEM 5.14
SECONDARY AIR SYSTEM
SECONDARY AIR SYSTEM
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.1
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SECONDARY AIR SYSTEM General: The secondary air system consists of all the compressor air that is not used to sustain combustion or for airframe use. Of all the air entering the engine the combustion process uses only 25%, 65% cools the combustion gases, the airframe uses 5% and the secondary air system uses the remaining 5%.
The Secondary Air System Provides Pressure Air For: - Cooling of hot section parts - Sealing of bearing compartment - Operates bleed valve and pre-swirl (jet flap) - Operates fuel purge valve - Operates fuel control unit (P3 Filter) Two sources of air used in the secondary air system: P2.5 Compressor Inter-stage air pressure P3 Compressor delivery pressure
This Section Is Divided Into 4 Parts: 1. Accessory gearbox breather 2. Oil tank pressurizing valve 3. Turbine cooling 4. Bearing compartment sealing
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.2
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SECONDARY AIR SYSTEM
P2.5
P2.5 P3 P3
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.3
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ACCESSORY GEARBOX BREATHER Function: Separates oil particles from air in the accessory gearbox before discharging overboard.
Description: - Centrifugal impeller - Mounted on the starter generator gear shaft - Starter generator gearshaft front end is sealed with a carbon face seal
Operation: Oil and air scavenged from the bearing cavities are directed to the accessory gearbox. The air/oil combination in the accessory gearbox causes foaming of the oil. The continuous flow of scavenged air and oil causes the accessory gearbox to pressurize. Prior to venting the air to the atmosphere, the oil must be separated from the air.
The relatively oil free breather air flows through the center of the impeller and out to the atmosphere via a cored passage in the accessory gearbox diaphragm.
Maintenance: - On condition - Replace carbon seal Blocked Or Restricted Breather Hose May: - Cause loss of oil through No. 1, 2 and 3 bearing cavities - Cause oil leak at flange "G" - Cause accessory drive seals to leak - Increase oil consumption - Cause an oil smell in the cabin
The pressure builds up in the accessory gearbox forces the air/oil mixture inside the breather impeller. The centrifugal force imparted by the impeller causes the heavier oil particles to be ejected back into the accessory gearbox.
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.4
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ACCESSORY GEARBOX BREATHER STARTER / GENERATOR GEAR CARRIER CARBON SEAL
BREATHER IMPELLER CARBON SEAL
BREATHER IMPELLER
CARRIER
CARBON SEAL
AIR AIR / OIL MIX PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.5
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OIL TANK PRESSURIZING VALVE Function: Reduces oil pressure fluctuation and oil consumption at high altitude.
Description: - Valve seat and spring loaded piston - Located in the inlet case (oil tank) at the 11 o'clock position - Maintains the oil tank pressure 5 to 7 psi above accessory gearbox pressure
The oil tank pressurizing valve maintains air pressure in the tank 5 to 7 psi above the accessory gearbox pressure. This positive pressure applied on the oil reduces pressure fluctuation and oil consumption at altitude. When static pressure in the tank reaches the specified limit, the piston compresses the spring, allowing oil tank air pressure to flow into the accessory gearbox. From the accessory gearbox, air flows through the centrifugal impeller and out to the atmosphere.
Troubleshooting: Operation: During normal operation, oil scavenge system collects air and oil from various bearing cavities. The accessory gearbox breather removes most of the air contained in the oil but some air remains trapped in the oil. When air and oil are carried from the cooler to the tank, it causes oil in the tank to foam. Foaming may cause cavitation of the pressure pump and fluctuation of oil pressure at high altitude.
Oil loss through overboard breather tube or the pressurizing valve being stuck open may cause oil pressure fluctuation at altitude.
Maintenance: - On condition - Remove and inspect valve - Ensure freedom of movement - Lap piston and seat
As altitude increases, air pressure in the tank drops and causes air trapped in the oil to expand (foam) and fill the tank completely. At this point, the excess foam transfers to the accessory gearbox thus causing an increase in oil loss through the centrifugal breather.
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.6
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OIL TANK PRESSURIZING VALVE
INLET CASE
PRESSURIZING VALVE HOUSING
SEAT
AGB DIAPHRAGM PISTON
AIR AIR / OIL MIX OIL
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.7
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TURBINE COOLING AND AIRBLEED SYSTEM Description: Internal passages in the engine distribute P3 air to provide cooling to the combustion chamber turbine and vane rings. After cooling, the air is evacuated in the gas path. Using the same distribution passages, P2.5 and P3 air are provided to the no. 1, 2 and 3 bearing labyrinth seals. Air flows into the bearing compartments is evacuated via the oil scavenge system and discharged overboard through the centrifugal breather impeller located in the accessory gearbox. Tapping on the gas generator case provides P2.5 and/or P3 air for external systems such as cabin environmental control system, de-icing system, door sealing, etc... Maintenance And Troubleshooting: - Keep P3 and P2.5 leaks to a minimum - (performance losses) - Ensure cooling rings in the combustion chamber are in satisfactory condition - Ensure no leak exists on airframe air bleed system
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.8
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TURBINE COOLING AND AIRBLEED SYSTEM
P2.5 P3 PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.9
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BEARING COMPARTMENT SEALING Function: Prevents oil from leaking outside the bearing cavities. Description: - Labyrinth seals - Consists of a multi-grooved ring running within a straight stator ring - Air pressure fills the air gap between the two parts
Possible Cause For Oil Loss Through Labyrinth Seals: - Lack of air flow through labyrinth seal (Not probable) - Wear on the knife's edges due to rotor unbalance or bearing distress - Oil coking in the grooves between the knife's edges - Flooding of bearing cavity due to malfunction in the oil scavenge system (most probable)
Problem Area Operation: The air seal consists of two separate parts, one stationary and one rotating. One of the two parts has machined grooves. A small clearance is maintained between the two parts and air pressure is blowing between them creating a high velocity air flow that draws the oil towards the inside of the bearing cavity.
Maintenance: - None - During HSI, ensure holes in the number 2 bearing area of gas Generator are not blocked - Keep accessory gearbox breather outlet free of obstruction - Do not over service the oil tank
PT6A-60 SERIES
Symptom
No. 1 Bearing
Oil smell in cabin Oily bleed valve and compressor
No. 2 Bearing (Rear)
Oil smell in cabin
No. 2 Bearing (Front)
Coking around no. 2 bearing and compressor turbine area Possible smoke on start and shutdown
No. 3 Bearing
Possible smoke on start and shutdown Oil in exhaust duct
TRAINING USE ONLY
ENGINE INDICATING 6.10
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BEARING COMPARTMENT SEALING
P3
NO.3 BEARING PT6A-60 SERIES
P2.5
P3
NO.2 BEARING TRAINING USE ONLY
NO.1 BEARING ENGINE INDICATING 6.11
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NOTES
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING 6.12
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ENGINE INDICATING SYSTEM
ENGINE INDICATING SYSTEM
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.1
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ENGINE INDICATING SYSTEM Function: - Provide the pilot with indications concerning the engine parameters during flight - Provide the required data for engine condition trend monitoring and performance
Engine Indicating Systems: - Ng / Np Tachometer-Generators (Pulse pick-up probes on the PC12) - Oil temp/ Oil pressure indication - Chip detector
Indicating Systems Built Into Engines: - Inter turbine temperature system (T5) - Torque indication system
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.2
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ENGINE INDICATING SYSTEM
COMPRESSOR SPEED NG (%) 9 0 21 8 7
2 3
OIL TEMPERATURE (C˚) AND PRESSURE (PSIG) OIL
0 1
2 % 3 6 5 4 RPM 11 X 100 4 10 5 9 8 7 6
ITT (C˚)
10 6 2
14
0 -2 x 10
20
11 12 ITT ˚c x 100 2 6 5 4 3
START
15 10 PSI 5 0
9 8 7
TORQUE (FT-LBS)
PROPELLER SPEED Np (RPM)
45 50 40 0 TORQUE 35 FTLB 5 x100
30 25
10 20 15
20 0 PROP RPM 15 X 100 10
5
Np TACHO GENERATOR
Ng TACHO GENERATOR
PT6A-60 SERIES
OIL PRESSURE TRANSMITER PORT
TRAINING USE ONLY
OIL TEMPERATURE BULB
ENGINE INDICATING SYSTEM 7.3
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INTER-TURBINE TEMPERATURE (T5) Function: Provides an indication of the Inter-Turbine Temperature (ITT), between the compressor turbine and the first stage power turbine vane ring (station 5).
Description: - 10 individual thermocouples (chromel-alumel) - 1 positive bus bar (chromel-small terminal) - 1 negative bus bar (alumel-large terminal) - 1 trim probe - 1 T5 wiring harness
Note: Engine operation at or above maximum temperature may damage or shorten hot section component's life
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.4
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TEMPERATURE INDICATING SYSTEM (T5)
WIRING HARNESS
THERMOCOUPLE TRIM PROBE
PRE-SB 13038 (A-60/61/65)
TERMINAL BLOCK
BUS-BAR
ALUMEL LEAD CHROMEL LEAD
THERMOCOUPLE JUNCTION PT6A-60 SERIES
TRAINING USE ONLY
INDIVIDUAL THERMOCOUPLE
ENGINE INDICATING SYSTEM 7.5
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
TEMPERATURE INDICATING SYSTEM (ITT) Operation: As temperature increases, an increasing voltage is generated at the chromel/alumel junction of each thermocouple. Uneven heat distribution within the gas path causes individual thermocouples to see different temperatures and generate different voltages. To obtain an average reading, the thermocouples are connected in parallel. The indication generated is the average temperature of 10 specific locations (thermocouple tips) within the gas path and therefore does not necessarily represent the exact average temperature at station 5. The exact average temperature is calculated at engine test and is used to determine engine acceptance. A trim probe located over the inlet case is connected in parallel with the 10 thermocouples to bias the average temperature reading. The resultant corrected temperature is read in the cockpit. The indication generated by the 10 probes at station 5 is trimmed down using the trim probe internal resistor. The smaller the resistance the greater the downtrim (the lower the ITT). The amount of trimming is a function of the trim probe internal resistance. The resistance of the trim probe is adjusted at engine test to match the required temperature trim.
PT6A-60 SERIES
Maintenance: - Check system loop resistance (continuity) - Check resistance of individual probe - Check insulation resistance (harness, probe and trim probe) - Check probes for heat response - Check Trim thermocouple adjustment
Troubleshooting: Problem Area
Symptom
Burnt Probes
T5 drops due to loss of probes in hot spots
Short Circuit To Ground
T5 drops due to complete or partial loss of T5 signal
Trim Probe Open Circuit
T5 increases due to loss of trimming function
High Resistance On T5 Circuit Between Engine And Aircraft Gage
T5 drops due to reduction of T5 signal
Trim Probe Resistance Drifting
T5 increases if trim resistance increases T5 drops if trim resistance drops
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.6
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
T5 SYSTEM SCHEMATIC
ALUMEL
CHROMEL
VARIABLE SEALED RESISTANCE (PRE SB 13338 & SB 14299)
BUS BARS & THERMOCOUPLES
TRIM PROBE
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.7
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
TORQUE SYSTEM Function:
Maintenance:
Provide an accurate indication of the torque applied to the propeller.
Check/calibrate the airframe torque transducer and gage (ref. to airframe maintenance manual).
Description: - Hydro-mechanical system - Floating first stage ring gear with helical splines - Piston - Cylinder - Spring loaded oil control valve
Troubleshooting: Problem Area Control Valve Stuck Open
Torque goes off scale (high)
Worn Piston Seal Rings
Torque indication low Set oil pressure to max limit
Operation: Torque applied to the propeller induces a small rotational and rearward movement of the first stage ring gear. This movement is due to the helical splines on the ring gear. The ring gear pushes the piston and the control valve. Moving the control valve to the rear, opens the metering orifice and allows more oil pressure to push on the piston against the ring gear mechanical force. The movement of the ring gear only stops when metered oil pressure in the torque meter chamber exactly balances the rearward force of the ring gear. Static air pressure inside the reduction gearbox acts on the torquemeter piston and would cause incorrect (higher) torque reading. For this reason, static pressure is sent to the transducer and subtracted from the torque reading. Hydrostatic lock is prevented by continuously bleeding oil from the pressure chamber. PT6A-60 SERIES
Symptom
Defective Transducer/Gage Oil In RGB Static Line
Torque may indicate high or low Torque fluctuation
Reference: A52, A64
1 psi = 30.57ft/lb
A60, A65
1 psi = 83.63ft/lb
A66
1 psi = 37.04ft/lb
A67
1 psi = 86.63ft/lb
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.8
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
TORQUE SYSTEM ELECTRIC TORQUE SIGNAL
TORQUE PRESSURE TRANSDUCER (AIRFRAME)
FIRST STAGE PLANET GEAR TORQUE METER OIL BLEED ORIFICE
1ST STAGE RING GEAR
REDUCTION GEARBOX STATIC PRESSURE RING GEAR MOVEMENT
TORQUE OIL PRESSURE
CONTROL VALVE
ENGINE OIL PRESSURE
TORQUE PISTON
LOW POWER PT6A-60 SERIES
CYLINDER
METERING ORIFICE
HIGH POWER TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.9
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
CHIP DETECTOR Function: Provides an indication of metal particle contamination of the engine oil system.
Description: - Two magnetic poles - Normally open circuit - Wired to a light in the cockpit (optional) - Self closing valve allows chip detector verification without draining the RGB (except A64/66)
Maintenance: - Inspect chip detector at interval specified by aircraft maintenance manual - Functionally test chip detector - 100hrs -> Check Continuity - 600hrs/12Mo. -> Function Check
Warning: DO NOT OVERTORQUE THE CHIP DETECTOR
Operation: When metal particles accumulate on the two magnetic poles and bridge the existing gap, the circuit closes. Some installations use an indicator in the cockpit to warn the pilot or maintenance people that contamination is present. Other models rely on visual inspection and continuity check of the chip detector to detect contamination. Particles found on the chip detector can be analyzed and identified. Refer to chapter 70 of the Engine Maintenance Manual.
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.10
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
CHIP DETECTOR
VALVE HOUSING
VALVE
VALVE CLOSED
MAGNETIC POLES
VALVE OPEN
PREFORMED PACKING
MAGNETIC CHIP DETECTOR
LOCKWIRE SECURING LUG
SELF CLOSING CHIP DETECTOR (A-52, A60, A61, A65 & CERTAIN A67 MODELS ONLY)
NON SELF CLOSING INSULATION CHIP DETECTOR (A64, A66 & CERTAIN A67 MODELS) ELECTRICAL CONNECTOR
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.11
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NOTES
PT6A-60 SERIES
TRAINING USE ONLY
ENGINE INDICATING SYSTEM 7.12
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
IGNITION SYSTEM
IGNITION SYSTEM
PT6A-60 SERIES
TRAINING USE ONLY
IGNITION SYSTEM 8.1
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
IGNITION SYSTEM Exciter Box Specifications: Input voltage.................................................... 9-30 VDC Input current .................................................... 3.5 amp Operating Altitude ........................................... 0-50000 feet Spark rate 10 VDC ....................................... 1 spark/sec 30 VDC .......................................... 4 spark/sec Stored energy.................................................. 4.7 joules Output voltage................................................. 8000 volts
Function: Provide the spark to ignite the fuel/air mixture. Description: - Airframe mounted ignition exciter - Two high tension cables - Two spark igniters Exciter Box: A sealed unit which transfers a DC low voltage input to a pulsed high voltage output. When the unit is energized, the capacitor progressively charges until the voltage can ionize the spark gap then the capacitor discharges through the igniter plugs. Ignition Cables: Two cables carry the electrical energy from the exciter box to the igniters. Each cable consists of an electrical lead surrounded by an insulating tube contained in a flexible metal braiding. Spark Igniters: Located at 4 and 9 o'clock positions on the gas generator case, the spark igniters are in the form of threaded plugs with a central electrode enclosed in an annular semi-conducting material. When the voltage reaches a certain level, the air between the central electrode and the plug outer shell ionizes a high energy spark discharges from the electrode.
PT6A-60 SERIES
Operation: Activated by the pilot for engine start. The system can operate continuously during adverse weather conditions to allow the engine to re-light in the event the of engine flame out. Maintenance: - Ignition plugs are not life limited. - Inspect cooling holes of spark igniters for blockage. - Inspect igniter shell and electrode for erosion. - Carry out functional test by disconnecting one ignition cable at the exciter box. Switch ignition on and listen for the spark. - Replace igniter plugs if dropped. - Check for fretting wear @ combustion chamber junction. Warning:
Wait six minutes after switching ignition off before handling any ignition components.
TRAINING USE ONLY
IGNITION SYSTEM 8.2
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
IGNITION SYSTEM
POWER TURBINE STATOR HOUSING
COMBUSTION CHAMBER LINER
IGNITERS
GASKET
SPARK IGNITER IGNITION CABLES 0.300 IN. MAX.
IGNITION EXCITER 0.015 IN. NEW IGNITER
PT6A-60 SERIES
ACCEPTABLE WEAR
WORN OUT
TRAINING USE ONLY
IGNITION SYSTEM 8.3
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NOTES
PT6A-60 SERIES
TRAINING USE ONLY
IGNITION SYSTEM 8.4
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE
PERFORMANCE
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.1
PERFORMANCE CHECK Function: Permits verification of engine condition over a wide range of ambient temperatures without exceeding torque or T5 limits.
- From appropriate curves (Airframe M/M), determine: Target Torque. ITT Ng Fuel Flow - Determine parameter limits using tolerance from the Airframe Maintenance Manual applied to the graph values. - Start engine and stabilize at idle for 5 min. - No generator or pneumatic loads during performance test. - Set torque and Np as per chart. - Stabilize engine at that power for 5 min. - Record actual ITT, Ng and Wf. - Compare recorded values of ITT, Ng and Wf to chart parameters. - If values deviate from chart limits, troubleshooting action should be undertaken to restore engine performance.
Performance Check Should Be Performed: - After engine installation. - Before and after hot section inspection. - After FCU change. - At regular interval.
Description: Performance check curves establish engine parameter limits for an acceptable engine at different atmospheric conditions. The check is performed at a given power where Tq and Np are constant and the values obtained for Ng, ITT and WF are compared to the limits obtained from the chart.
Pre-H.S.I. Checklist: Procedure: - Ensure engine indicating system is properly calibrated. - Determine Outside Air Temperature (OAT). - Determine Pressure Altitude (Pa) or Barometric Press Set altimeter to 29.92 inHg to obtain Pressure Altitude Set altimeter to 0 ft altitude to get field barometric pressure
PT6A-60 SERIES
1. 2. 3. 4. 5.
Calibrate engine gauges. Check for F.O.D. and wash compressor if needed. Check the oil filter/screens and chip detectors. Borescope (optional) Carry out a ‘before’ and ‘after’ Performance run.
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.2
ENGINE PERFORMANCE CHECK (TYPICAL)
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.3
PERFORMANCE CHECK (SHORTS INSTALL) General: Shorts installations use two types of performance checks. 1. Static Reduced Power Check.(Static RTOP) 2. Static Maximum Take Off Power check (Static MTOP) 3. Reserve Power Check
Static Maximum Take Off Power Check: A Static MTOP check is required upon replacement of an engine after the Static Reduced Torque Check has been carried–out, or if a loss of performance is noted.
1. Determine OAT and pressure altitude 2. From POH, determine target torque and corresponding Ng, Wf and ITT target values. 3. Start and stabilize engine at target torque (1 min.) 4. Check that observed values of Ng, Wf and ITT agree with the graph values within tolerance. 5. If unacceptable, refer to PWC EMM for performance troubleshooting flow chart.
Static Reduce Power Check: This check is performed on both engines after; a) installing an engine. b) a rigging adjustment. c) a propeller or engine component change. d) if requested by the flight crew.
Reserve Power Check: Procedure: 1. Determine OAT and pressure altitude 2. From POH, determine target torque and ITT limit. 3. Start and stabilize engine at target torque (1 min.) 4. Record ITT and compare it to pre-determined limit. Must be within POH tolerances (approx +10 / -50°C). If out of limit, carry-out a Static MTOP check.
PT6A-60 SERIES
The Reserve Power Check is a ‘follow-up’ to a satisfactory MTOP/RTOP check. Set power as per POH, (2nd engine must be at Idle/ off.) b) Activate Power Reserve Switch, confirm Static MTOP is achieved. a)
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.4
PERFORMANCE CHECK (SHORTS INSTALL)
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.5
PERFORMANCE CHECK (SHORTS INSTALL)
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.6
ENGINE CONDITION TREND MONITORING (WEBECTM) Data Acquisition:
Function: -
Maintenance tool Allows user to monitor the engine performance Permits early detection of engine deterioration Helps determine trouble area Increase dispatch reliability Allows to perform repairs at the most economical time Allows to be on (soft time) for hot section inspection
Description: WebECTM is a process of periodically recording engine and aircraft instrument parameters and comparing them to a computer reference model. Under specific ambient conditions, engine parameters such as compressor speed (Ng), Inter-turbine Temperature (ITT) and fuel flow (Wf) are predictable. The difference between the actual engine parameters and the computer model values will be plotted as 3 deltas using a graphical chart method as illlustrated below.
The accuracy of the WebECTM process depends on the quality of the data entered into a computer system. Cruise condition is the only flight configuration where engine reaction can be predicted. To ensure validity of WebECTM data: - Record data once per day, or every 6 hours - Select the flight with the longest cruise that is at a representative altitude and airspeed - Allow the engine to stabilize 3 to 5 minutes without ANY power lever movements - The same flight configuration must be repeated (i.e. electrical load, bleed air extraction) - Record data within a reasonable time frame Data entry and Calculation: Via PWC WebECTM Plotting and Trend Analysis:
Once a trend is established by the plotting of these deltas, any deviation would indicate some engine deterioration. Analysis of the trend reveals extent of deviation and possible need for corrective action.
PT6A-60 SERIES
Once the deltas are calculated, the computer does the plotting and displays the result on screen or prints it. Analysis of the trend can reveal extent of deviation and possible need for corrective action.
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.7
WEBECTM (CON’T) Plotting: Following computation, DELTA Ng, DELTA ITT, and DELTA Wf should be plotted on a continuous sheet. Flight log number may be used as the abscissa, although the trend could also be recorded as a function of date or, preferably, as a function of engine running time in hours.
Guidelines for interpretation of trend: Net change of 10 to 15°C ITT: Early sign of deterioration, that should be investigated when convenient. Net change of 20 to 25°C ITT: Deterioration becoming more serious. Further running could result in replacement of high cost hot section component. Corrective action should be taken as soon as possible
Definition Of Terms: Base Line: A straight line, derived from the average of the first 15 delta points for a particular engine with known conditions, which include a recently completed HSI, inspection of compressors and a compressor wash. New or newly overhauled engines also meet these conditions. Net Change: The change from the base line to a line passing through a delta point at a specific location on the graph. Revision of Base Line: In the event the initial base line position improperly estimated, a revision of the base line values needs to be done. A fault or change in the instrumentation calibration or an engine repair/H.S.I. will require the baseline to be re-established.
Net change of 30°C ITT: At this level, whether or not ITT is redlined, deterioration has progressed to a point where serious engine damage is imminent Net change of .75 to 1% Ng: Early signal of some deterioration should be investigated when convenient Net change over 1.5% Ng: Action should be taken as soon as possible Note: WebECTM courses are available. Please contact P&WC Customer Training department for the schedule
Analysis: The analysis of the trend graph should be carried-out on a daily basis if possible, but not deferred for more than five days.
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.8
ECTM SAMPLE PLOT
COMPRESSOR WASH
HSI
Ng %
4 2 0 -2 -4
ΔITT ˚C
50 25 0 -25 -50
ΔWf pph
50 10 0 -10 -20
TIME PERIOD
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE 9.9
TBO AND HSI INTERVAL • SB 13003 for PT6A-65 • SB 13303 for PT6A-52/60/61 • SB 13203 for PT6A-60AG, A-65AG • SB 14003 for PT6A-67R, 67D • SB 14303 for PT6A-67AF, F • SB 14603 for PT6A-64, 66, 66A/B/D, 67, 67A/B/P/T • SB 14503 for PT6A-67AG TBO Industry: Initial TBO applicable to all operators. TBO Fleet: TBO attained by individual operators for engines of the same model in their fleet only. TBO Extension: Operators desiring TBO extension can submit a formal request in writing together with details of sample engine log book to: Manager, Technical Support, PT6 engines. Recommendations for time between-overhaul take into consideration the average effect of the many variables that affect overhaul life. These variables are average flight duration, percentage of time at any given power level, climatic conditions and environment, maintenance practices and engine utilization. Under extreme conditions of very low utilization coupled with continuous operation in salt water atmosphere or heavy sand environment periodic inspections in accordance with the applicable maintenance instructions may indicate that maintenance actions are required prior to the recommended overhaul life. PT6A-60 SERIES
Engine
TBO
H.S.I.3
PT6A-52/60/61
3600
1800
PT6A-65
6000
12002/20001
PT6A-64/66/66A/66D/67/67A/67T
3000
1500
PT6A-67B/P, PT6A-64 ( post SB 14089 or 14112 and 14261, 14308 )
3500
1750 to 2000
PT6A-66B, PT6A-66 ( post SB 14112, 14274 and Piaggio PostSB80-0194 )
3600
1800 to 2000
PT6A-60AG/65AG/67AF/67AG/F
3000
1500
PT6A-67D/R
6000
2000
1) A65’s operated as airliners. 2) A65’s operated as executive transports. 3) N/A if operated under an approved WebECTM program
HSI interval may be based on engine condition trend monitoring with borescope inspection at 2000 hours and every 500 hours subsequently. (Ref SB 14003). Modular Concept: An engine may be operated as 2 distinct modules, each having a logbook. This allows an operator to return the power section or gas generator for repair (or overhaul) and keep the remaining module in service. Any spare module of the same model can be installed and operated as long as each logbook reflects the applicable data.
TRAINING USE ONLY
PERFORMANCE 9.10
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OPERATING LIMITS* Description: Operating limits define the upper and lower boundaries for all engine parameters observed in the cockpit during normal operation for each specific engine model. Excursion beyond these limits may accelerate engine wear and possibly lead to component malfunction. For current operating limits, refer to applicable aircraft pilot operating handbook. *Operating limits, listed here, are for reference only. They can be found in each Maintenance Manual in Section 7100-00.
PT6A-60 SERIES
TRAINING USE ONLY
PERFORMANCE 9.11
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OPERATING LIMITS PT6A-52 Power Setting Take-off/Max Cont Max Climb Max. Cruise Normal Cruise Min. Idle Starting Transient Max. Reverse
SHP 850 850 850 850 800
Torque lb-ft 2230 2230 2230 2230 2750 -
psig 72.95 72.95 72.95 72.95 89.73 -
Max ITT °C 820 775 800 775 750 1000 850 760
Ng RPM 39000 39000 39000 39000 21000 39000 -
% 104 104 104 104 51 104 -
NP RPM 2000 2000 2000 2000 2205 -
Oil Pressure PSI 90 to 135 90 to 135 90 to 135 90 to 135 200 (max) 40 to 200 90 to 135
Oil Temp. °C 0 to 110 0 to 110 10 to 99 10 to 99 -40 to +110 -40 (min) 0 to 110 0 to 99
Torque lb-ft 3625 3625 3625 3625 3625 -
psig 43.34 43.34 43.34 43.34 43.34 -
Max ITT °C 820 820 785 820 775 750 1000 850 760
Ng RPM 39000 39000 39000 39000 39000 19000 39000 -
% 104 104 104 104 104 51 104 -
NP RPM 1700 1700 1700 1700 1700 1870 1650
Oil Pressure PSI 90 - 135 90 - 135 90 - 135 90 - 135 90 - 135 60 (min) 200 (max) 40 – 200 90 - 135
Oil Temp. °C 0 – 110 0 – 110 0 – 110 0 – 110 10 – 99 -40 - 110 -40 (min) -40 - 110 0 - 99
Torque lb-ft 3625 3625 3625 3625 -
psig 43.34 43.34 43.34 43.34 -
Max ITT °C 820 775 775 775 750 1000 850 760
Ng RPM 39000 39000 39000 39000 21750 39000 -
% 104 104 104 104 58 104 -
NP RPM 1700 1700 1700 1700 1870 1650
Oil Pressure PSI 90 - 135 90 - 135 90 - 135 90 - 135 60 (min) 200 (max) 40 – 200 100 - 135
Oil Temp. °C 0 – 110 0 – 110 0 – 110 0 – 110 -40 - 110 -40 (min) 0 - 110 0 - 104
PT6A-60A Power Setting Take-off Maximum Continuous Takeoff / Climb Max. Cruise Normal Cruise Min. Idle Starting Transient Max. Reverse
SHP 1050 1050 1000 1000 1000 900
PT6A-60AG Power Setting Take-off Maximum Continuous Takeoff / Climb Max. Cruise Min. Idle Starting Transient Max. Reverse
PT6A-60 SERIES
SHP 1050 1050 1050 1050 900
TRAINING USE ONLY
PERFORMANCE 9.12
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OPERATING LIMITS PT6A-61 Power Setting Take-off/Max Cont. Max. Cruise Normal Cruise Max Climb Min. Idle Starting Transient Max. Reverse
SHP 850 850 850 850 800
Torque lb-ft 2230 2230 2230 2230 2750 -
psig 72.95 72.95 72.95 72.95 89.73 -
Max ITT °C 800 800 775 775 715 1000 850 760
Ng RPM 39000 39000 39000 39000 19000 39000 -
% 104 104 104 104 51 104 -
NP RPM 2000 2000 2000 2000 2250 -
Oil Pressure PSI 90 - 135 90 - 135 90 - 135 90 - 135 60 (min) 200 (max) 40 – 200 90 - 135
Oil Temp. °C 0 – 110 10 – 104 0 - 99 0 – 104 -40 - 110 -40 (min) 0 - 110 0 - 99
Torque lb-ft 2230 2230 2230 2750 -
psig 72.95 72.95 72.95 89.96 -
Max ITT °C 800 800 785 715 1000 870 760
Ng RPM 39000 39000 39000 19000 39000 -
% 104 104 104 51 104 -
NP RPM 2000(90.7%) 2000 2000 2205(100%) 1900
Oil Pressure PSI 100 - 135 100 - 135 100 - 135 60 (min) 200 (max) 40 – 200 100 - 135
Oil Temp. °C 0 – 110 0 – 104 10 – 104 -40 - 110 -40 (min) -40 - 110 0 – 104
PT6A-64 Power Setting Take-off Max. Continuous MaxClimb/Cruise Min. Idle Starting Transient Max. Reverse
PT6A-60 SERIES
SHP 700 700 700 700
TRAINING USE ONLY
PERFORMANCE 9.13
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OPERATING LIMITS PT6A-65B Power Setting Take-off Maximum Continuous Maximum Climb Norm cruise Min. Idle Starting Transient Max. Reverse
SHP @ OAT 1100 1100 1000 1000 900
Torque lb-ft 3625 3625 3625 3625 5100 -
43.34 43.34 43.34 43.34
Max ITT °C 820 810 800 750 700 1000 870 760
Ng RPM 39,000 39,000 39,000 39,000 21,750 39,000 -
% 104 104 104 104 58 104 -
NP RPM 1700 1700 1700 1700/100% 1870/110% 1650/97%
Oil Pressure PSI 90 to 135 90 to 135 90 to 135 90 to 135 60 minimum 200 max 40 to 200 90 to 135
Oil Temp. °C 0 to 110 0 to 110 0 to 110 10 to 99 -40 to 110 -40 minimum 0 to 110 0 to 99
Ng RPM 39,000 39,000 39,000
% 104 104 104
NP RPM 1700/100% 1700 1700
Oil Pressure PSI 90 to 135 90 to 135 90 to 135
Oil Temp. °C 10 to 110 10 to 110 10 to 105
21,000 39,000 -
56 104 -
1870/110% 1650/97%
60 minimum 200 max 40 to 200 90 to 135
-40 to 110 -40 minimum -40 to 110 10 to 105
PT6A-65AR Power Setting Take-off Maximum Continuous Maximum Cruise/ climb Min. Idle Starting Transient Max. Reverse
PT6A-60 SERIES
SHP 1424 1220 956 900
Torque lb-ft 4400 3825 3625
52.61 45.74 43.34
Max ITT °C 855 840 770
5100 -
61.00 -
715 1000 870 760
TRAINING USE ONLY
PERFORMANCE 9.14
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OPERATING LIMITS PT6A-65AG Power Setting Take-off Maximum Continuous Maximum Cruise/ climb Min. Idle Starting Transient Max. Reverse
SHP 1300 1220 956 900
Torque lb-ft 4017 3825 3625
48.03 45.74 43.34
Max ITT °C 810 810 800
5100 -
60.98 -
750 1000 870 760
Ng RPM 39,000 39,000 39,000
% 104 104 104
NP RPM 1700/100% 1700 1700
Oil Pressure PSI 90 to 135 90 to 135 90 to 135
Oil Temp. °C 0 to 110 0 to 110 0 to 110
21,000 39,000 -
56 104 -
1870/110% 1650/97%
60 minimum 200 max 40 to 200 90 to 135
-40 to 110 -40 minimum -40 to 110 10 to 110
Ng RPM 39,000 39,000 39,000
% 104 104 104
NP RPM 2000/90.7% 2000 2000
Oil Pressure PSI 90 to 135 90 to 135 90 to 135
Oil Temp. °C 0 to 104 0 to 104 0 to 104
PT6A-66A Power Setting Take-off Maximum Continuous Maximum Cruise/ climb Min. Idle Starting Transient Max. Reverse
SHP 850 850 850 800
lb-ft 2230 2230 2230
Torque 60.21(72.95) 60.21(72.95) 60.21(72.95)
Max ITT °C 830(800) 830(800) 820(785)
2750 -
74.24(89.96) -
750(759) 1000 870 760
19,000 39,000 -
51 104 -
2205/100% 1900/86.2%
60 minimum 200 max 40 to 200 90 to 135
-40 to 110 -40 minimum 0 to 110 0 to 104
Ng RPM 39,000 39,000 39,000
% 104 104 104
NP RPM % 2000 90.7 2000 90.7 2000 90.7
Oil Pressure PSI 100 to 135 100 to 135 100 to 135
Oil Temp. °C 0 to 104 0 to 104 0 to 104
19,000 39,000 -
51 104 -
2205 1900
60 minimum 200 max 40 to 200 100 to 135
-40 to 110 -40 minimum 0 to 110 0 to 104
PT6A-66D Power Setting Take-off Maximum Continuous Maximum Cruise/ climb Min. Idle Starting Transient Max. Reverse
PT6A-60 SERIES
SHP 850 850 850 800
lb-ft 2230 2230 2230
Torque 72.95 72.95 72.95
Max ITT °C 850 840 840
2750 -
90.0 -
750 1000 870 780
TRAINING USE ONLY
100 86.2
PERFORMANCE 9.15
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OPERATING LIMITS PT6A-67A Power Setting Take-off Max Cont Max. Cruise / Climb Norm Cruise / Climb Min. Idle Starting Transient Max. Reverse
SHP 1200 1200 1000 1000 900
Torque lb-ft 3708 3708 3625 3625 5100 -
44.34 44.34 43.35 43.35 60.98 -
Max ITT °C 850 840 840 820 750 1000 870 760
Ng RPM 39,000 39,000 39,000 39,000 19,000 39,000 -
51 104 -
NP RPM 1700/100% 1700 1700 1700 1870/110% 1650/97%
Oil Pressure PSI 90 to 135 90 to 135 90 to 135 90 to 135 60 minimum 200 max 40 to 200 90 to 135
Oil Temp. °C 10 to 110 10 to 110 10 to 105 10 to 105 -40 to 110 -40 minimum 0 to 110 10 to 105
Ng RPM 39,000 39,000
% 104 104
NP RPM 1700/100% 1700
Oil Pressure PSI 90 to 135 90 to 135
Oil Temp. °C 10 to 110 10 to 110
19,000 39,000 -
51 104 -
1870/110% 1650/97%
60 minimum 200 max 40 to 200 90 to 135
-40 to 110 -40 minimum 0 to 110 10 to 105
% 104 104
PT6A-67AG Power Setting Take-off Max Cont/ Cruise/ climb Min. Idle Starting Transient Max. Reverse
PT6A-60 SERIES
SHP 1350 1220 900
lb-ft 4170 3770
Torque 49.87 45.07
Max ITT °C 800 800
5100 -
60.98 -
750 1000 870 760
TRAINING USE ONLY
PERFORMANCE 9.16
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OPERATING LIMITS PT6A-67B Power Setting Take-off Maximum Continuous Maximum Cruise/ climb Min. Idle Starting Transient Max. Reverse
SHP 1200 1200 1000
Torque lb-ft 3708 3708 3090
5100
psig 44.34 44.34 36.95
61.00
900
Max ITT °C 800 800 760 750 1000 870 760
Ng RPM 39000 39000 39000
% 104 104 104
19000
51
39000
104
Ng RPM 39000 39000 39000
% 104 104 104
NP RPM 1700/100% 1700 1700
Oil Pressure psig 90 to 135 90 to 135 90 to 135
Oil Temp. °C 10 to 110 10 to 110 10 to 110
1870/110% 1650/97%
60 min. 200 max. 40 to 200 90 to 135
-40 to 110 -40 min. 0 to 110 10 to 105
NP RPM 1700/100% 1700 1700
Oil Pressure psig 90 to 135 90 to 135 90 to 135
Oil Temp. °C 10 to 110 10 to 110 10 to 110
1870/110% 1650/97%
60 min. 200 max. 40 to 200 90 to 135
-40 to 110 -40 min. -40 to 110 10 to 105
NP RPM 1700/100% 1700/100% 1700/100%
Oil Pressure psig 90 to 135 90 to 135 90 to 135
Oil Temp. °C 10 to 110 10 to 110 10 to 110
1870/110% 1650/97%
60 min. 200 max. 40 to 200 90 to 135
-40 to 110 -40 min. -40 to 110 10 to 105
PT6A-67D Power Setting Take-off Maximum Continuous Maximum Cruise/ climb Min. Idle Starting Transient Max. Reverse
SHP 1279 1214 1106
Torque lb-ft 3950 3750 3750
5100
psig 47.23 44.84 44.84
61.00
900
Max ITT °C 800 780 760 750 1000 870 760
19000 39000 -
51 104-
PT6A-67F Power Setting Take-off Maximum Continuous Maximum Climb/ Cruise Min. Idle Starting Transient Max. Reverse
PT6A-60 SERIES
SHP 1600 1600 1550 1350
Torque lb-ft 4943 4943 4789 4634
6092 900
psig 60.25 60.25 58.37 56.48
74.25
Max ITT °C 870 870 815 795 750 1000 910 760
Ng RPM 39000 39000 39000 19000 39000 -
TRAINING USE ONLY
% 104 104 104 50.7 104-
PERFORMANCE 9.17
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OPERATING LIMITS PT6A-67P Power Setting Take-off Maximum Continuous Maximum Climb/ Cruise Min. Idle Starting Transient Max. Reverse
SHP 1200 1200 1200 1000
Torque lb-ft 3708 3708 3708 3090
5100
psig 44.34 44.34 44.34 36.95
61.00
900
Max ITT °C 850 840 820 820 750 1000 870 760
Ng RPM 39000 39000 39000
Ng RPM 39000 39000 39000 39000 21000 39000 -
19000 39000 -
NP RPM 1700/100% 1700/100% 1700/100%
Oil Pressure psig 90 to 135 90 to 135 90 to 135
Oil Temp. °C 10 to 110 10 to 105 10 to 105
1870/110% 1650/97%
60 min. 200 max. 40 to 200 90 to 135
-40 to 110 -40 min. -40 to 110 10 to 105
% 104 104 104 104
NP RPM 1700/100% 1700 1700 1425
Oil Pressure psig 90 to 135 90 to 135 90 to 135 90 to 135
Oil Temp. °C 10 to 110 10 to 110 10 to 110 10 to 105
56 104 -
1870/110% 1650
60 min 200 Max 40 to 200 90 to 135
-40 to 110 -40 min. 0 to 110 10 to 105
% 104 104 104 51 104-
PT6A-67R & T Power Setting Take-off Alt. take-off (R only) Maximum Continuous Maximum Cruise/ climb Min. Idle Starting Transient Max. Reverse
PT6A-60 SERIES
SHP 1424 1281 1220 1020
lb-ft 4400 3960 3825 3760
Torque psig 52.61 47.35 45.74 44.96
Max ITT °C 855 825 840 790
900
5100 -
61.00 -
755 1000 870 760
TRAINING USE ONLY
PERFORMANCE 9.18
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
ROTOR COMPONENTS - SERVICE LIFE Description:
Flight Count Factor:
Certain rotating components are subject to low-cycle fatigue due to cyclic operation of the engine. Additionally, other factors such as high frequency fatigue and metallurgical changes related to time rather than flight cycles are considered. As a result, these parts must be removed from service when the cycle limit is reached.
This is an index of severity. An indication of how much a component is affected during the engine operation. This is a multiplier and will change for a given component if installed in a different engine.
Reference: - SB 13002 for PT6A-52/60/61/65 - SB 13202 for PT6A-65AG - SB 14002 for PT6A-64,66,67, 67B/D/P - SB 14302 for PT6A-67AF - SB 14502 for PT6A-67AG/67F
If your missions include more flights than starts, component cycle life may be calculated in accordance with the following formula: Total Cycles = [Starts + ( Flights-Starts ) ] x Flight Count Factor Abb. Cycle Factor
Airworthiness Regulations Require The Operator To: - Log engine hours, starts and aircraft flights - Calculate and record these hours and cycles
Operators having missions, which include many touch-andgo flights or a frequency of scheduled in-flight shutdowns (such as used during pilot training) or which include more than 10 flights per hour must submit their mission profiles to Pratt and Whitney Canada for life cycle analysis.
Definition Of A Cycle: A flight preceded by a start and followed by a shutdown.
Abbreviated Cycle: A flight, from wheels up to wheels down, but without a start or shutdown.
PT6A-60 SERIES
TRAINING USE ONLY
PERFORMANCE 9.19
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OVERTORQUE CHART (TYPICAL)
75
3000
OUTPUT TORQUE (FT-LBS)
TORQUEMETER PRESSURE (PSI)
S TO A HIP POW N OV ER ERH SECT AUL IO FAC N ILITY
RECORD IN LOG BOOK
NO ACTION REQUIRED
0 0
PT6A-60 SERIES
20 SECONDS
0 1
2
3
4
5
TIME (MINUTES)
TRAINING USE ONLY
PERFORMANCE 9.20
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OVERTEMPERATURE CHART (TYPICAL)
2000 C A INTER TURBINE TEMPERATURE ( C° )
A B NO ACTION REQUIRED
* ITT RED LINE 0
5
10
15
20
25
30
TIME (SECONDS) A = DETERMINE & CORRECT CAUSE OF OVERTEMPERATURE - START OVERTEMP, INSPECT P.T. BLADES THROUGH EXHAUST - RECORD IN LOG BOOK B = PERFORM HOT SECTION INSPECTION C = SHIP ENGINE TO AN OVERHAUL FACILITY * ITT RED LINE = MAXIMUM TAKE OFF ITT
PT6A-60 SERIES
TRAINING USE ONLY
PERFORMANCE 9.21
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
ENGINE TROUBLESHOOTING Effective engine troubleshooting infers monitoring engine parameters on a regular basis, using performance check and engine condition trend monitoring.
Troubleshooting of problems related to internal engine components is generally divided in 2 areas: - Compressor section - Hot section.
Effective troubleshooting can be divided into four steps: 1. Evaluate the symptoms 2. Logically isolate the possible cause of the problem 3. Try quick fixes when possible. 4. Determine the corrective action required to solve the problem Remember that troubleshooting is done by comparing engine parameters with a set of reference values for a good engine or by looking at the trend of the parameters of one engine over a period of time.
The compressor section refers to all the components of the main gas path. This starts from the aircraft inlet and includes the gas generator where P3 air fills the cavity around the combustion chamber liner. The hot section is composed of all the components starting from the combustion chamber liner down to the exhaust duct including all the vane rings and the turbines.
Propeller speed and torque are the indication of power produced by an engine. Any serious troubleshooting should begin with the calibration of the instruments used in the process.
Note: Chapters 10 and 11 cover troubleshooting of fuel and propeller systems.
PT6A-60 SERIES
TRAINING USE ONLY
PERFORMANCE 9.22
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PERFORMANCE TROUBLESHOOTING Introduction: - The following information is a guide only. - Refer to the appropriate aircraft or engine maintenance manual as necessary.
Troubleshooting: - Technique used to logically isolate the cause of an engine problem . - Determine the corrective maintenance action(s). - Resolve the problem in a timely manner.
Shotgun Approach: - Based on a "Trial and Error" method. - Used by personnel with minimal knowledge of engine operation and troubleshooting techniques. - This time consuming method is not cost effective and indicates that some form of training is required.
Systematic Approach: - Preferred approach - Gathering of all applicable information - Analysis of engine symptoms - Determination of most probable cause - Corrective actions - Confirm results This method requires a good knowledge of normal and abnormal engine operation, systems operation as well as the ability to use technical manuals efficiently. The systematic approach increases the chances that you are looking in the correct area for the problem, so that precious man-hours and material are not wasted on tasks that provide no resolution to the problem.
By The Book Approach: Effective but time consuming method used by maintenance technicians who follow all necessary troubleshooting procedures from technical manuals. This method requires some knowledge of engine construction and operation.
PT6A-60 SERIES
TRAINING USE ONLY
PERFORMANCE 9.23
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE TROUBLESHOOTING (CONT’D) The Basics: - Understand the problem - Simultaneous review of ECTM* and recent past history - Pilot reports, and maintenance logs A review of the ECTM plots for the past three to six months in conjunction with a review of the past thirty days of pilot write-ups and maintenance actions are the two most useful tools to be employed in defining the problem and setting a plan for corrective action. It is recommended these records be available on-site where the aircraft maintenance is being performed and not in a locked office a few hundred miles away where the individual has gone home for the night. If this is not the case, then the maintenance crew should have some way of accessing the information. ECTM has the ability to tell you if the problem is in the cold section or hot section of the engine. A step shift of only one parameter is a likely instrumentation problem. Pilot write-ups and maintenance logs can offer very valid clues; for example if the pilot report has been repeated several times dated back to seven days previous. One could go back and review the maintenance actions carried out just prior to the first pilot report to see if the problem was introduced by the maintenance action. Compressor Health: * Inspection for FOD and erosion * Increased manual limits * Compressor may have reached refurbishment point One of the first areas that one should look at on the engine is the compressor intake. PWC has extended the accepPT6A-60 SERIES
tance limits on compressor FOD. The extended limits are approximately double the previous ones but are acceptable providing that engine performance remains acceptable. Therefore, if the FOD is towards the high side of the extended limits, heavy erosion is visible or the engine is having performance difficulties then it is likely the compressor has reached the refurbishment point. Further attempts to repair the engine on-wing would be futile. Compressor Wash: - How long since last wash - Does ECTM show extended gradual shift right of all parameters - Experience has shown 15 to 20 °C recovery when washed - A wash may be all you need If it has been some time since the last wash and the compressor looks dirty, it is recommended a ground performance run be carried out, followed by engine wash, and then finally by another ground performance run. A comparison of the pre and post wash run data will indicate how dirty the engine was and if any further troubleshooting is required. We have seen reported "major performance loss" being rectified by nothing more than two successive engine washes. Note: ECTM = Engine Condition Trend Monitoring
TRAINING USE ONLY
PERFORMANCE 9.24
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE TROUBLESHOOTING (CONT’D) Instrument Calibration: - How long since last calibration. - Accurate calibrations are worth the effort. - OAT, PA, and IAS are used in normalization process and thereby affect ECTM accuracy . - Erroneous OAT, PA, and TQ affects targets for the day. - If ECTM data shows a step jump in ITT only, one should suspect an instrumentation problem in the ITT system. - Similarly if all parameters are high, a torque indication problem is likely. Remember ECTM plots are produced by normalization process of certain inputs and then comparing the normalized data with actual recorded. Outside air temperature, pressure altitude, prop speed, and airspeed are inputs to the normalization formula. If these parameters are out of calibration, the ECTM plots will be unreliable as a troubleshooting tool. Outside air temperature and pressure altitude are used to determine target torque for the day in doing ground performance runs. Errors in these instruments will lead to selection of the wrong target torque for the day. If the torque transducer calibration is low, the actual engine torque will be higher than what is indicated. This is perceived as the engine being temperature limited, as well, fuel flow and gas generator speed will be higher than normal.
PT6A-60 SERIES
From the previous example, the importance of instrument calibration can not be overemphasized.
Intake Deviations: - Actual running data has shown up to 35° C ITT differential between separator deployment and retraction - Ice vane drop/out of adjustment will also cause performance deterioration and parameter fluctuation
Eliminate Cabin Bleed Leaks: - Ground run with cabin bleeds blanked at engine flange - Compare blanked and un-blanked run data - Leaking P3 pre-coolers and defective temp control valves have caused up to 60°C rises in ITT
Carry out a ground performance run with the cabin bleed systems in the normal off position. Follow this with a ground performance run with the bleeds blanked at the engine flange. It is important to blank the system at the engine flange rather than at some other convenient location.
TRAINING USE ONLY
PERFORMANCE 9.25
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE TROUBLESHOOTING (CONT’D) Eliminate Cabin Bleed Leaks (Cont'd): Compare the results of the two runs. If the parameters of the run with the bleeds blanked appear lower, you have a leak or component malfunction in the bleed system that requires rectification. At the same time as the bleeds blanked run is done, it is also a convenient opportunity to do a bleed valve closing point check and a T5 trim determination check. Bleed Valve Closing: - Is the BOV closure point correct ? - Late closing bleed valve results in high ITT. - Sticking bleed valve results in intermittent power. - Regular scheduled BOV checks. - Closure point shifts with time. - Some engines have classified CT baffle. - Controls BOV closing pressure air. - Facilitates seat adjustment. - Mixing pre and post SB hardware results in BOV closing problems.
Trim Determination: - Trim on/off runs to determine if trim compensation is correct. - Not a "dial as required system" - Do not readjust existing trim probes.
Do two ground runs at take-off power, one with the trim compensator connected and one with it disconnected and compare the results. It is recommended to use a precision tester (i.e. Barfield) to monitor ITT during these runs rather than the cockpit gauge. The delta in ITT between these two runs should be within ±10% of engine data plate trim value. If the delta is greater than ±10%, the T5 trim compensator should be replaced. Previously installed or adjusted trim compensators must not be readjusted.
Some engine models have a classified baffle bolted to the number two bearing cover. The size of the inner diameter of this baffle controls the air to the bleed valve, therefore, when working in this area pay particular attention not to intermix pre and post SB hardware. Intermixing of hardware results in BOV timing difficulties.
PT6A-60 SERIES
TRAINING USE ONLY
PERFORMANCE 9.26
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERFORMANCE TROUBLESHOOTING (CONT’D) Borescope Inspection: - Borescope engine to confirm hot section distress. - Does what you see with the borescope agree with the ECTM plots. - Do you want to run to extended borescope limits. If the ECTM plots show typical hot section deterioration (rising ITT and decreasing NG) you should see distress of the Compressor Turbine (CT) vane and/or CT blades when you borescope the hot section. Some maintenance manuals have the extended inspection limits incorporated (72-00-00). A number of factors must be taken into consideration when opting to run to the extended limits. The two factors are whether there is a large ITT delta upshift in the ECTM plots and how long the engine has been operating this way. If the borescope inspection reveals a burned through vane airfoil one must carefully assess the decision to continue in service. As this condition excites the CT blade that can lead to blade cracking and possible failure. Engine Matching: - Has engine performance been questionable since last HSI. - What classes of CT and PT vanes were installed at last test cell run. - What vane classes are installed now. - Use same class within ± .03 CT and ± .1 PT - Keep a log of important engine data, BOV seat, CT baffle, vane class etc.
PT6A-60 SERIES
Engines are assembled; performance tested and trimmed with a particular set of CT and first stage PT vane classes. It is important to know what these classes were as a reference point for future on-wing maintenance. When it becomes necessary to replace a CT or Power Turbine (PT) vane on-wing, one must go back to the last test cell performance run vane class matching as a reference for replacement, not necessarily the class that was removed. PWC recognize that it is not always possible to obtain the exact same class vane as required on short notice. To allow some flexibility, PWC recommends that one stays within ±0.03 of a class on CT and ±0.1 of a class on PT of those installed at last test cell run. Maintaining a small spreadsheet for your complete fleet is a useful tool and worth the effort. The spreadsheet should contain engine serial number with what class vanes were installed at last test cell run and what classes are currently installed. It can give ready picture of what engines may not be ideally matched. It can also speed up the process in hot section planning.
TRAINING USE ONLY
PERFORMANCE 9.27
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NOTES
PT6A-60 SERIES
TRAINING USE ONLY
PERFORMANCE 9.28
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FUEL SYSTEM
FUEL SYSTEM
PT6A-60 SERIES
TRAINING USE ONLY
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FUEL SYSTEM 10.1
POWER MANAGEMENT - 3 lever control system - 2 levers on PT6A-66 and A-67B/P Power Lever: - Controls the compressor speed in forward as well as reverse thrust mode. - Controls the propeller pitch in reverse. - Connects to a cam cluster located on the accessory gearbox. - Cam cluster transmits power lever movement to the fuel control unit. - The FCU controls Ng. Below idle, movement of the power lever affects both Ng and the beta valve to change the propeller blade angle from positive pitch to reverse pitch as power is gradually increased in reverse.
Propeller Lever: - Connected to the propeller speed control lever on the top of the propeller governor (CSU). - Controls the propeller speed in the governing mode. - Allows feathering of the propeller. Manual Override (Power Lever): - Single engine aircraft only. - Controls Ng directly in the event of a loss of P3 air pressure at the FCU. - Controls fuel flow from minimum to maximum flow stops. - Used in forward mode only. Note: Engines operated with two levers have a ‘single speed’ propeller governor. (Pilatus PC-XII aircraft PT6A-67B/P).
Fuel Lever (Condition Lever): - Cut-off position stops fuel flow to the combustion chamber and causes the engine to shut down - Allows to set Ng from low idle to high idle - Low idle is the minimum Ng allowed - High idle is the minimum power used in flight When the correct Ng is reached, the low idle position is selected to allow fuel into the combustion chamber.
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL SYSTEM 10.2
POWER MANAGEMENT MIN. POWER TAXI RANGE POWER RANGE REVERSE MAX. POWER BETA
MIN. RPM FEATHER
MAX. RPM
PROPELLER LEVER
POWER LEVER CAM ASSY
PROPELLER GOVERNOR
LOW IDLE SHUT-OFF
HIGH IDLE
FUEL CONDITION LEVER
PT6A-60 SERIES
TRAINING USE ONLY
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FUEL SYSTEM 10.3
FUEL SYSTEM Function:
Alternate/Emergency Fuels:
Provides the engine with clean fuel at the required pressure and flow to permit control of engine power.
Minimize use of AVGAS. AVGAS may contribute to accelerate hot section deteriorations. Run AVGAS a maximum of 150 hrs between overhauls.
Components: - Fuel heater - Fuel pump - Fuel control unit - Flow divider - Fuel nozzles (14) - Fuel drain valves (2)
Operating time on AVGAS is computed on the basis of quantity used versus average engine consumption. The operation of P&WC commercial engines, covered by this training manual, on fuel other than the approved jet fuels is not permitted without the express permission of P&WC.
Fuel And Additives: - SB 13044 for A-52/60/61/65. - SB 13244 for A-65AG. - SB 14004 for A-64/66/67. - SB 14504 for A67AG/F - SB’s indicated above list minimum requirements for acceptable engine fuel. - Additives such as; anti-corrosion. anti-icing. thermal stability additives. Anti-microbial - Use of Aviation Gasoline (AVGAS) is limited to 150 hours per engine between overhaul periods (TBO). - Diesel fuel is permitted for agricultural use only.
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL SYSTEM 10.4
FUEL SYSTEM
CONDITION LEVER
BYPASS PORT
POWER LEVER
Py AIR TO CSU
FUEL OUT
FUEL MANIFOLD ADAPTER
FUEL PUMP
DRAIN VALVES
P3 IN FUEL CONTROL UNIT
FUEL IN
AIR
FUEL CONTROL UNIT(FCU) A
PT6A-60 SERIES
FUEL DELIVERY TUBE
P3 AIR TO FCU
FUEL HEATER FUEL FROM TANK (AIRFRAME)
VIEW A
FLOW DIVIDER
FUEL FROM FUEL PUMP TO FCU TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
AIR FUEL
FUEL SYSTEM 10.5
FUEL SYSTEM Description: Fuel from the aircraft tank is sent to the fuel heater via one or more airframe boost pumps. From the fuel heater, fuel is directed to the fuel pump. The fuel pump sends the fuel to the fuel control unit (FCU) which determines the quantity of fuel required by the engine to produce the power requested through the power lever and according to the ambient conditions. The excess fuel is returned to the inlet of the fuel pump and the fuel flow going to the engine goes through the fuel flow meter to indicate the fuel consumption in the cockpit. Then, the fuel reaches the flow divider where it is directed to the primary and secondary fuel manifolds to supply all the nozzles. The fuel nozzles atomize the fuel in the combustion chamber to sustain the combustion.
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL SYSTEM 10.6
FUEL SYSTEM SCHEMATIC
FUEL HEATER OIL OUT
FUEL CONTROL UNIT
FUEL PUMP UNIT INLET FILTER (SELF RELIEVING)
OIL IN
PUMP
FUEL METERING OUTLET FILTER
INPUTS NG PLA
BYPASS
BYPASS PRESSURE REGULATING VALVE
FUEL LEVER P3 AIR
FUEL TANK BOOST PUMP (AIRFRAME)
PRIMARY MANIFOLD
COMBUSTION CHAMBER FUEL INLET PRESSURE OIL INLET PRESSURE PUMP DELIVERY PRESSURE BYPASS FUEL METERED FUEL PRIMARY FUEL MANIFOLD SECONDARY FUEL MANIFOLD
PT6A-60 SERIES
FLOW METER (AIR FRAME)
PPH
FUEL DISTRIBUTION SECONDARY MANIFOLD
FLOW DIVIDER
IGNITERS
P3 AIR
DUMP OR
ACCUMULATOR
FUEL NOZZLES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL SYSTEM 10.7
FUEL HEATER Function: - Heat the fuel to prevent ice crystal formation - Heat the FCU housing to prevent condensation from freezing in the bellows assembly - Preheat the fuel for FCU calibration
Troubleshooting: - Verify operation by touching the fuel filter bowl after shutdown. Should be warm but not hot (≈27°C / 80°F). - A template temperarure recorder can be used to determine if thermal element is good (refer to the Maintenance Manual). - Internal damage may cause oil to mix with fuel and result in high oil consumption when engine is running. - Internal damage may also cause fuel to mix with the oil in static conditions.
Description: - Housing - Fuel passages - Scavenge oil passages - Thermal element sensing fuel temperature
Operation: Cold fuel from the aircraft boost pump enters the fuel heater and surrounds the thermal element. The cold thermal element contracts and allows scavenge oil from the accessory gearbox to travel across the heat exchanger. Heat from the oil transfers to the fuel raising it's temperature. At 21°C the thermal element begins to expand and moves the valve to the right. In this position, scavenge oil from the accessory gearbox progressively bypasses the fuel heater and the fuel temperature begins to stabilize. The spring located at the back of the valve pushes it back to the left (heating position) when the fuel temperature drops. During operation, the thermal element constantly reacts to adjust fuel outlet temperature.
PT6A-60 SERIES
Maintenance: - Replace unit if defective. - Repair the coating on fuel heater as per engine Maintenance Manual.
Symptom
Cause
Effect
Fuel Too Hot
Thermal element or control valve
Fuel pump cavitation
Fuel Too Cold
Thermal element or control valve
Possible filter blockage (ice)
High Oil Consumption
Heat exchanger internal leakage
Oil leak in the fuel
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL SYSTEM 10.8
FUEL HEATER
FUEL OUTLET
OIL INLET SLIDE VALVE
THERMAL ELEMENT
PUSH ROD
RETURN SPRING
OIL OUTLET
FUEL OUT OIL IN
FUEL IN
OIL OUT
FUEL INLET
FUEL PASSAGE OIL PASSAGE
PT6A-60 SERIES
TRAINING USE ONLY
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL SYSTEM 10.9
FUEL PUMP Function: Provide clean fuel under pressure to the fuel control unit. Description: - Single stage - Gear type pump - Brass bushings loaded against pump gears - Carbon seals prevent fuel leak - Inlet and outlet fuel filters
Pump Capacity (Typical): Ng %
Wf pph
Pressure psi
13 %
200
175
100 %
1600
800
Typical engine Wf at 1000 SHP ≈ 500 pph Inlet Filter: - 74 micron screen. - Cleanable (600hrs) - Bypass feature - Bypass at 1.5 psid Outlet Filter: - 10 micron non-metallic type filter - Disposable (600hrs)
PT6A-60 SERIES
Outlet Filter Bypass Valve: - Bypass fuel if filter gets restricted - Set to open at 15-25 psid
Bypass Pressure Regulating Valve: - Maintains bypass pressure above a minimum to minimize fuel leakage at the brass bushing - Set to open at 10 - 35 psid
Operation: From the fuel heater, fuel enters the fuel pump housing and passes through the inlet filter, then through the pump. Fuel is filtered a second time through the outlet filter before being delivered to the fuel control unit. Two carbon face seals prevent fuel from leaking out of the pump. A bypass pressure regulating valve is mounted on the FCU bypass return line to ensure a minimum amount of pressure is maintained on the brass bushings to reduce fuel leakage when pump pressure increases.
Maintenance: - Inspect inlet and outlet filters at specified intervals. - Inspect for reddish-brown stain in drain port of fuel pump (Sundstrand pumps only). - Replace fuel pump if the engine is operated without airframe boost pressure for more than 10 hours.
TRAINING USE ONLY
FUEL SYSTEM 10.10
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL PUMP HIGH PRESSURE FUEL TO FCU OUTLET FILTER
FILTER BYPASS VALVE
CARBON SEAL CARBON SEAL BRASS BUSHINGS
COUPLING TO ACCESSORY GEARBOX
FCU BYPASS RETURN
FUEL INLET PRESSURE BYPASS FUEL PUMP DELIVERY PRESSURE
INLET FILTER (SELF RELIEVING) BYPASS PRESSURE REGULATING VALVE LOW PRESSURE FUEL FROM FUEL HEATER
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.11
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL CONTROL UNIT (MAIN FLOW) Function: Deliver the required amount of fuel at the required pressure to the fuel nozzles.
Pressure Relief Valve: - Prevents system over pressurization - Dumps excess fuel to the bypass - Factory set to open at 1350 psid
Bypass Valve: - Maintains delta pressure P1-P2 constant at 53 psid - Bypass fuel in excess of engine requirement - Fuel pump delivers more fuel than required - Bypass fuel returns to the pump - Factory adjusted to limit engine acceleration rate During acceleration, more fuel is required in the P2 line. To supply the need, less fuel is dumped to Po by the bypass valve. During deceleration, the opposite applies.
PT6A-60 SERIES
Minimum Flow: - Provides minimum fuel to start engine and prevents flame out during rapid deceleration - Factory set at ≈90 pph
Pump Unloading Valve: - Pilot operated to start or shutdown the engine - Opens when pilot shuts down the engine - Dumps P2 fuel to P0 - P2 becomes equal to P0 - Shutdown valve closes - Factory set
Minimum Pressurizing And Shutdown Valve: - Allows the fuel control to pressurize before providing fuel to the engine - Improves fuel metering on start - Works in conjunction with the pump unloading valve for engine shut down - Opens at 100 psid
TRAINING USE ONLY
FUEL SYSTEM 10.12
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL CONTROL UNIT (MAIN FLOW)
LOW
Po
Po P2 PUMP UNLOADING VALVE
HIGH PRESSURE RELIEF VALVE
Po
TO FUEL PUMP BYPASS
P1
P1 PUMP DELIVERY PRESSURE
Po
P2 METERED FUEL PRESSURE P0 BYPASS FUEL PRESSURE
MINIMUM FLOW
Py MODIFIED Px
P2
Py
FROM FUEL PUMP BYPASS VALVE
P1
FUEL METERING UNIT
P1
P2
Po MINIMUM PRESSURIZING AND SHUTDOWN VALVE
P2
P2 Py
PT6A-60 SERIES
TRAINING USE ONLY
TO FUEL DISTRIBUTION SYSTEM
TO PROPELLER GOVERNOR
FUEL SYSTEM 10.13
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL CONTROL UNIT (METERING) Function:
Fuel Valve And Bellows Section:
Determines fuel flow to the engine in response to the following inputs: - Power Lever Position (PLA) - Compressor discharge pressure (P3) - Compressor speed (Ng)
The Fuel Valve rotates and moves up and down to determine the amount of fuel going to the engine by varying the opening between the inner rotating valve and the static outer valve. Cockpit movement of the PLA causes the 3D cam to rotate. Rotation of the 3D cam makes the Cam Follower move which in turn rotates the Fuel Valve (Initial accel or decel).
3D Cam And Follower: Rotates around it's centerline and up and down in response to power lever movement and compressor speed (Ng). The 3D cam is rotated by moving the power lever in the cockpit. The face of the cam is shaped to move the cam follower and rotate the fuel valve, thus changing fuel flow and Ng. The 3D cam also senses Ng speed via a flyweight governor. Variation of Ng speed causes the Po orifice to open or close causing the 3D cam to translate up or down. The cam follower and fuel valve move in response to the 3D cam therefore changing fuel flow and Ng.
PT6A-60 SERIES
Up and down movement of the Fuel Valve depends on the bellows position (P3 air pressure). - More Wf Increasing P3 moves the Valve Seat down, allowing Pz pressure to diminish, resulting in a downward movement of the Fuel Valve. - Less Wf Decreasing P3 moves the Valve Seat up, allowing Pz pressure to increase, resulting in an upward movement of the Fuel Valve.
TRAINING USE ONLY
FUEL SYSTEM 10.14
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL METERING SECTION
INC
REASE
P1 FROM PUMP
Po
POWER LEVER P1
P2 3D CAM FOLLOWERS P1 PUMP DELIVERY SYSTEM P2 METERED FUEL PRESSURE Pt FUEL SERVO PRESSURE Po BYPASS FUEL Py GOVERNING AIR PRESSURE P3 COMPRESSOR DISCHARGE PRESSURE Pz FUEL INTERMEDIATE PRESSURE
PT6A-60 SERIES
FUEL VALVE FOLLOWER
3D CAM
FUEL VALVE
Pt BLEED TO Po COMPRESSOR SPEED NG
P2 METERED FUEL OUTLET
RPM
COMPRESSOR PRESSURE
Pz
DRAIN
Py
FLYWEIGHT GOVERNOR
P3 PSI
TRAINING USE ONLY
P3 SENSOR BELLOWS P3 AIR FILTER
FUEL SYSTEM 10.15
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
METERING SECTION (3D CAM)
INCREASE NG 3D CAM FOLLOWER POWER LEVER FUEL VALVE FOLLOWER
E
ED
S REA ON D EC WF SP E A
FOLLOWER SPRING
B
DECREASE NG
IN C R E A S E W
F
D
3D CAM
FLY WEIGHT PT BLEED TO Po A- DECEL B- STEADY STATE C- ACCEL D- INTERMEDIARY
FUEL VALVE
NG GOVERNOR P3 SENSOR BELLOWS
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.16
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL CONTROL SYSTEM
FUEL CONTROL UNIT (FCU) FUEL METERING FUEL CONDITION LEVER AND HIGH IDLE CAM
FUEL PUMP LOW MAIN FLOW
PUMP Po UNLOADING VALVE
Po P2
P1 POWER LEVER
FUEL VALVE FOLLOWER
FUEL VALVE Pt BLEED TO Po FLYWEIGHT GOVERNOR DRAIN
PT6A-60 SERIES
P3
P3 AIR FILTER P3 SENSOR BELLOWS
P1
P2
Pt
BYPASS VALVE
P2
P1 Po P2 Pz Py
COMPRESSOR PRESSURE (P3)
PUMP
Po
Po MINIMUM FLOW
COMPRESSOR SPEED (NG)
Po
P1
3D CAM
3D CAM FOLLOWER
HIGH PRESSURE RELIEF VALVE
FUEL INLET (FROM FUEL HEATER)
MINIMUM PRESSURIZING AND SHUTDOWN VALVE
TO DISTRIBUTION SYSTEM Py
P2
TO PROPELLER GOVERNOR
TRAINING USE ONLY
FUEL SYSTEM 10.17
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
COMPRESSOR DELEVERY AIR LINES Function: To provide clean P3 air to the FCU. Description: Compressor discharge air (P3), derived from the diffuser section of the gas generator case, is routed to the metering section of the FCU through external lines and a fine-screen filter. The system consists of two tube assemblies, one on each side of the air filter housing. Maintenance: Replace P3 filter - SB’s 13175 and 14054 introduce a P3 air pressure sensitive drain valve to the air filter housing. During compressor wash, P3 air pressure is low, and the valve is spring-loaded open to allow cleaning fluid to drain. As engine speed builds, P3 air pressure increases and closes the valve. Note: The filter element is normally a permanent (stainless steel) type and is intended to be cleaned ultrasonically at an approved overhaul facility. However, the filter may be cleaned (washed) electronically at field level.
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.18
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
P3 AIR FILTER ELEMENT
P3 AIR FILTER ELEMENT
(PRE−SB 13175 & PRE-SB 14054)
PT6A-60 SERIES
(POST−SB 13175 & POST-SB 14054)
TRAINING USE ONLY
FUEL SYSTEM 10.19
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FLOW DIVIDER WITH DUMP VALVE Function:
Operation:
Provides a means to separate the starting flow (primary) from the normal engine running flow (Pri & Sec). Allows the fuel flow to be ported to a collector can during the shutdown (dump) sequence.
When the condition lever is moved to the "fuel on" position, fuel enters the flow divider and pushes against the primary and secondary valve and spring. At a fuel pressure of 9 13 psi, the primary valve moves to the right and allows fuel to flow to the primary manifold only.
Description: - Two concentric valves spring loaded to the closed position - Fuel pressure operated
As Ng speed increases, fuel pressure increases (17-22 psid) in the flow divider and the secondary valve moves to the right. At this point, Ng is at approximately 35% and fuel flows through all the nozzles.
Primary Flow: Allows fuel to flow through primary manifold for starting. Primary valve opens at fuel pressure of 9 - 13 psi
When the fuel lever is moved to the "cut-off" position, the fuel pressure drops rapidly and the two springs push the primary and the secondary valves toward the closed position. This allows the fuel to drain by gravity into a collector can, preventing contamination (carbon deposits) of fuel nozzles due to fuel residue.
Secondary Flow: Combined with the Primary flow, allows enough fuel flow to operate the engine. Secondary valve opens at fuel pressure of 17 - 22 psid.
Maintenance: - No maintenance at field level - Visually inspect for cracks and leaks
Dump Position: Allows fuel to dump into a collector can. Springs move the Primary and Secondary valves to the cut-off position, porting both manifolds to dump.
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.20
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FLOW DIVIDER AND DUMP VALVE FLOW DIVIDER AND DUMP VA LVE
FUEL NOZZLE FUEL NOZZLE SHEATH
PRIMARY MANIFOLD PORT
SECONDARY MANIFOLD PORT PRIMARY FUEL MANIFOLD
FUEL DUMP (To collector can) P2 FUEL IN
PRIMARY FUEL MANIFOLD SECONDARY FUEL MANIFOLD DUMP FUEL
GAS GENERATOR CASE SECONDARY FUEL MANIFOLD
INLET ADAPTER FUEL FLOW DIVIDER
SECONDARY VALVE
PT6A-60 SERIES
COMBUSTION CHAMBER OUTER LINER ASSEMBLY
PRIMARY VALVE FUEL DUMP
P2 FUEL IN
TRAINING USE ONLY
FUEL SYSTEM 10.21
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FLOW DIVIDER WITH PURGE VALVE (SB 13074, 14065) Function: Provides a means to separate the starting flow (primary) from the normal engine running flow (Pri & Sec). Allows the fuel flow to be purged (blown) back to the Combustion Chamber to be burnt during the shutdown sequence. Description: - Two concentric valves spring loaded to the closed position - A P3 purge check valve separates the fuel side from the air side - Fuel/Air pressure operated Primary Flow: Allows fuel to flow through primary manifold for starting. Primary valve opens at fuel pressure of 9 - 13 psi, and forces shut the P3 purge check valve. Secondary Flow: Combined with the Primary flow, allows enough fuel flow to operate the engine. Secondary valve opens at fuel pressure of 17 - 22 psid. Purge: - P3 air accumulator (airframe). - Opens the check valve. - Purges the fuel from transfer tubes and nozzles into the Combustion Chamber.
PT6A-60 SERIES
Operation: When the fuel lever is moved to the "fuel on" position, fuel enters the flow divider and pushes against the primary and secondary valves. At a pressure of 9 - 13 psi, the primary valve moves to the right and allows fuel to flow in the primary manifold at a pressure providing optimum fuel atomization. As Ng speed increases, fuel pressure goes up and at 17 22 psid, the secondary valve moves to the right. At this point, Ng is spooling through 35% and fuel flows through all the nozzles. When the fuel lever is moved to the cut-off position, fuel pressure drops and the two springs push the primary and secondary valves into the purge position. P3 air, accumulated in a purge can, pushes the check valve open and blows the remaining fuel in the manifold and fuel nozzles in the combustion chamber where it is burned. This may cause a small Ng and T5 spike during shutdown. Maintenance: - No maintenance at field level - Visually inspect for cracks and leaks - Verify airframe check valves and purge canister.
TRAINING USE ONLY
FUEL SYSTEM 10.22
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FLOW DIVIDER AND PURGE VALVE
FUEL NOZZLE FUEL NOZZLE SHEATH SECONDARY MANIFOLD PORT
COMBUSTION CHAMBER OUTER LINER ASSEMBLY
PRIMARY MANIFOLD PORT PRIMARY FUEL MANIFOLD
GAS GENERATOR CASE
P3 AIR SECONDARY FUEL MANIFOLD
P2 FUEL IN INLET ADAPTER FUEL FLOW DIVIDER
PRIMARY FLOW POSITION SECONDARY VALVE PRIMARY VALVE
CHECK VALVE P3 AIR
P2 FUEL IN PRIMARY AND SECONDARY FLOW POSITION
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.23
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
SIMPLEX FUEL NOZZLES (A52/60/61, A64, A65) Function: Deliver and atomize metered fuel into the combustion chamber.
Construction: - 14 fuel nozzle adapters, 7 primary, 7 secondary - 14 sheaths - 14 fuel nozzle tips - 28 transfer tubes (manifolds)
Maintenance: - Clean or replace nozzles every 400 hours - New operator clean every 200 hours - Alternate cleaning method, in situ cleaning every 200 hours to extend intervals between removals - Leak test if nozzles tips are removed - Check for erosion and fretting wear on nozzle sheaths - Upgrades from Simplex to Duplex type nozzles: SB 13182…….A65’s SB 14053…….A64 SB 14067…….A66/67,A,R,AF Warning:
Operation: On start, fuel flows through the primary manifolds and the seven primary fuel nozzles. The position of the primary fuel nozzles is such that fuel is sprayed circumferentially towards the spark igniters in order to facilitate ignition.
Badly Spraying Nozzles Will Reduce Hot Section Component Life
An increase in Ng causes fuel pressure to increase and the secondary fuel nozzles to spray fuel into the combustion chamber. During operation, all 14 fuel nozzles receive fuel from the flow divider and deliver it to the combustion chamber.
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.24
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
SIMPLEX FUEL NOZZLES
PRIMARY FUEL MANIFOLD ADAPTER
TRANSFER TUBE (SECONDARY)
FUEL MANIFOLD ADAPTER
WORKING PRESSURE 9 PSI
TRANSFER TUBE (PRIMARY)
20
0
30+ PSI
WORKING PRESSURE 17 PSID
TRANSFER TUBE (SECONDARY)
FUEL NOZLE SHEATH
PRIMARY FUEL MANIFOLD SECONDARY FUEL MANIFOD
PT6A-60 SERIES
10
FUEL MANIFOLD ADAPTER
TRANSFER TUBE (PRIMARY)
TRAINING USE ONLY
FUEL SYSTEM 10.25
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
DUPLEX FUEL NOZZLES (A67B/D/F/P AND POST SB FOR OTHERS) Function: Deliver and atomize metered fuel into the combustion chamber.
Construction: - 14 fuel nozzle adapters - 14 fuel nozzle sheaths - 14 fuel nozzle tips - 28 transfer tubes
Maintenance: - Clean or replace nozzles every 400 hours. - New operator should clean every 200 hours. - Alternate cleaning method, in situ cleaning every 200 hours to extend intervals between removals. - Leak test if nozzles tips are removed. - Check for erosion and fretting wear on nozzle sheaths. Warning: Badly spraying nozzles will reduce Hot Section component life
Operation: On start, the flow divider sends fuel to the primary manifolds. The 14 fuel nozzles will deliver fuel to the combustion chamber through the Primary passage. As Ng increases, the fuel pressure increases. The secondary fuel nozzle passages will spray fuel into the combustion chamber. During operation, both Primary and Secondary passages of the 14 fuel nozzles receive fuel from the flow divider and deliver it to the combustion chamber.
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.26
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
DUPLEX FUEL NOZZLES
FUEL MANIFOLD ADAPTER
TRANSFER TUBE (SECONDARY)
WORKING PRESSURE 9 PSI +
FUEL MANIFOLD ADAPTER
TRANSFER TUBE (PRIMARY)
20
0
30+ PSI
TRANSFER TUBE (SECONDARY)
FUEL NOZLE SHEATH
PRIMARY FUEL MANIFOLD SECONDARY FUEL MANIFOD
PT6A-60 SERIES
10
TRANSFER TUBE (PRIMARY)
TRAINING USE ONLY
FUEL SYSTEM 10.27
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL CONTROL UNIT MANUAL OVERRIDE The P1 to Pz pressure differential will move the fuel valve down to increase fuel flow.
Function: Allows the pilot to manually control the FCU fuel valve in the event of a pneumatic (P3, Py) system malfunction.
Installed on the following: - A-60AG - A-64 - A-65AG SB 13196 - A66A, A66D - A-67B/P - A-67AG
A return spring below the P2 valve ensures the valve follows the bellows movement during normal operation. In the event of a pneumatic failure (P3 or Py), it is easier to compress the return spring than the bellows; so less force is required to move the MOR and the Pz valve.
Caution: Move manual override lever slowly
Operation: In the event of a P3/Py air loss or metering unit malfunction, the pilot can manually control the position of the fuel valve by simulating the action of P3 air pressure. A special lever is provided in the cockpit to that effect.
Maintenance: - Operate manual override system regularly to confirm proper operation and familiarize with engine response in this mode
Movement of the Manual Override Lever (MOL) will increase spring pressure on the rate piston, forcing it to move. The rate of movement is established by the orifice which dampens any abrupt MOL movement. The rate piston movement is transmitted to the Manual Override Rod (MOR) that runs through the center of the fuel valve. The MOR forces the P2 valve down allowing Pz pressure to bleed to Po.
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.28
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FCU MANUAL OVERRIDE MANUAL OVERRIDE LEVER
RATE PISTON Po Po
MANUAL OVERIDE ROD P1
ORIFICE P2 Pz
Py
P3 AIR Pa
PT6A-60 SERIES
SPRING
TRAINING USE ONLY
P1 PUMP DELIVERY SYSTEM P2 METERED FUEL PRESSURE Pz FUEL INTERMEDIATE PRESSURE Po BYPASS FUEL Py GOVERNING AIR PRESSURE P3 COMPRESSOR DISCHARGE PRESSURE
FUEL SYSTEM 10.29
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
POWER RECOVERY SYSTEM (PT6-A65R/AR AND 67R ONLY) Function: On twin engine aircraft’s, provides manual or automatic power increase on one engine in the event of a severe power loss from the opposite engine.
Description: A solenoid valve activated by a low torque reading on the failed engine allows P3 air to push on a piston located at the back of the FCU. The piston then rotates an eccentric shaft changing the position of the cam follower on the 3D cam. The movement of the follower on the cam is designed to cause a rotation of the fuel valve and increases Ng by approximately 4%. The system is used during take-off only. A P3 bleed to atmosphere allows the servo piston to return when power recovery is selected off (solenoid valve closed).
Maintenance: Check and adjust Ng increase as per Airframe Maintenance Manual.
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.30
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
POWER RECOVERY SYSTEM
P1 FROM PUMP
P1 CAM FOLLOWER FUEL VALVE FOLLOWER POWER LEVER
Po
3D CAM P2 TO FUEL NOZZLES
Po
PT
Pz
FUEL VALVE BLEED TO ATMOSPHERE
VALVE SEAT SOLENOID VALVE (AIRFRAME)
P1 PUMP DELIVERY SYSTEM P2 METERED FUEL PRESSURE Pt FUEL SERVO PRESSURE Pz FUEL INTERMEDIATE PRESSURE Po BYPASS FUEL Py GOVERNING AIR PRESSURE P3 COMPRESSOR DISCHARGE PRESSURE
PT6A-60 SERIES
NG GOVERNOR
Py TO PROPELLER GOVERNOR
DRAIN
P3 FILTER
P3 SENSOR BELLOWS P3 AIR
TRAINING USE ONLY
FUEL SYSTEM 10.31
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OVERTORQUE LIMITER Function: A back-up unit which prevents engine overtorques. The pilot is always responsible for operating the engine within limits.
Description: A oil bellows which senses torquemeter oil pressure and is linked to a Py bleed orifice. Found on the following engines: - A-64 - A-66B/D - A-67AF post SB 14056 - A-67B post SB 14154 - A-67T
A solenoid (deleted by SB 14185) valve is used on the A67B and A-67AF to disable the torque limiter when not required. The solenoid valve closes when de-powered. It controls the supply of Py to the torque limiter.
Maintenance: - Adjust unit as per Airframe Maintenance Manual so that the required torque value is not exceeded. - Pressure check unit to ensure Py does not leak. - Replace unit if defective.
Operation: Oil from the torquemeter chamber passes through a restrictor before entering the bellows. The restrictor dampens torque pressure fluctuation and prevents damage to the bellows assembly. When torque pressure reaches a specified limit above maximum permitted torque, the bellows expands and compresses the spring. The flapper valve then moves to allow Py air pressure from the fuel control unit to bleed to the atmosphere and therefore limit the fuel supply to the engine. Bimetallic disks are mounted on the spring to compensate for variation of spring tension caused by change in ambient temperature.
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.32
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
OVERTORQUE LIMITER (A-64, 66A/B/D, 67AF, 67B/R/T) ADJUSTMENT SCREW
FLAPPER VALVE
Py AIR FROM FCU
Py AIR FROM FCU
ADJUSTMENT SCREW BIMETALLIC DISKS
TORQUEMETER OIL PRESSURE
BELLOWS TORQUEMETER OIL PRESSURE
OVERTORQUE POSITION PT6A-60 SERIES
RESTRICTOR NORMAL POSITION
TRAINING USE ONLY
FUEL SYSTEM 10.33
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL CONTROL UNIT ADJUSTMENT
Deadband
- Adjust deadband first, by deadband adjustment screw. - Clockwise increases the deadband angle. - Always verify low idle after a deadband adjustment.
Low Idle
-
Always adjust before high idle setting Loosen FCU lever clamping screw To increase Ng, loosen top screw, tighten lower one To decrease Ng, loosen lower screw, tighten top screw When adjusting Ng, turn screw in increments of 1/6 of a turn at a time
High Idle
-
High idle can be adjusted at two location on the FCU Adjust at cam follower adjustment screw if there is no stagger in the condition lever. Adjust High idle stop screw if the condition levers are staggered. Clockwise rotation increases Ng 1.5% per turn
Maximum Ng, Reverse Ng, Reserve Power
- Adjust as per Airframe Maintenance Manual
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.34
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
TYPICAL FUEL CONTROL UNIT ADJUSTMENTS
FUEL CONDITION LEVER
DEADBAND ADJUSTMENT FCU LEVER
POWER LEVER
MAX Ng (FORWARD)
IF THERE IS STAGGER HIGH IDLE STOP
CAM FOLLOWER ADJ. MAX Ng REV (HIGH IDLE) IF NO STAGGER
HIGH IDLE CAM
RESERVE POWER STOP
SPEED RESET SERVO
Py P3 AIR
(LOW-IDLE) NG DOWN NG UP
{
CUT OFF STOP
FOR LOW IDLE ADJUSTMENT
(LOOSEN ONE SIDE AND TIGHTEN OTHER SIDE)
PT6A-60 SERIES
TRAINING USE ONLY
FUEL SYSTEM 10.35
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
FUEL SYSTEM TROUBLESHOOTING SUMMARY Observed Problem
Verification
Engine Does Not Start / Hot Starts
-
Engine Hangs Below Idle (Hung Start 30-35% Ng)
- Ensure starting procedure is carried out properly - Flow divider secondary valve not opening
Engine Is Slow To Accelerate To Idle
-
Sub-Idle Condition (40-45% Ng)
- P3/Py line leaking or broken. P3 filter blocked - Prop. Governor or Torque Limiter leaking Py. - FCU bellows broken or leaking
White Smoke On Shut Down From Exhaust Duct
- Verify for proper operation of flow divider and dump/ purge valve - Replace FCU
Ng Coupling Failure
- Engine will go to 85% power
Fuel Leakage Between FCU And Fuel Pump
- Remove FCU from pump and replace o-ring at fuel bypass port - Replace FCU and pump if fuel leakage persists
PT6A-60 SERIES
Ensure that minimum cranking speed is achievable Verify igniters for proper operation Check for evidence of fuel flow to the flow divider while motoring the engine Ensure primary and secondary fuel nozzles are in their respective position (N/A for engines equipped with duplex nozzles) - Replace flow divider - Replace fuel nozzles - Weak batteries
Ensure starting procedure is carried out properly Check for possible restriction in the P3 air line to the FCU Possible Py leaks Replace flow divider Replace FCU
TRAINING USE ONLY
FUEL SYSTEM 10.36
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER SYSTEM
PROPELLER SYSTEM
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.1
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER SYSTEM Function: Change the power produced by the engine into thrust in order to propel the aircraft through the air.
Description: - Three to six bladed propellers - Made of Aluminium or Composite materials - Variable pitch, single acting type - Propeller governor (CSU) controls: Propeller Speed in governing mode. Blade Angle in Beta mode.
List Of Topics: - Propeller system - Pitch change mechanism - Governing mode - Beta mode - Primary blade angle - Reverse thrust - Feathering - Propeller overspeed governor - Np governor - Propeller governor adjustments
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.2
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER SYSTEM PROPELLER BLADE
PROPELLER GOVERNOR
PITCH CHANGE MECHANISM
SPINNER
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.3
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PITCH CHANGE MECHANISM Function: Allow varying the propeller blade angle in order to maintain a constant Np through various ambient conditions and power settings.
Description: - Hollow spider hub supports the blades - Feathering spring attached to the servo piston (dome) - Centrifugal counterweights on each blade working with the feathering spring drive the propeller blade toward feather - Oil pressure from the propeller governor drives the propeller towards reverse position
When oil pressure is decreased, the return spring and counter weights force the oil out of the servo piston and change the blade pitch to a coarser position. An increase in oil pressure drives the blades towards a finer pitch.
CSU Action
Propeller Reaction
Max Position
Oil In
Finer Pitch (lower pitch) (faster prop RPM)
Reverse
Oil Out
Coarser Pitch (higher pitch) (slower prop RPM)
Feather
Operation: Oil from the propeller governor feeds into the propeller shaft and to the servo piston via the oil transfer sleeve mounted on the propeller shaft.
Maintenance: - Refer to the Airframe Maintenance Manual.
As oil pressure increases, the servo piston is pushed forward and the feather spring is compressed. Servo piston movement is transmitted to the propeller blade collars via a system of levers.
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.4
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PITCH CHANGE MECHANISM
PROPELLER GOVERNOR (CSU) MOVES FORWARD FROM PBA TO REV
PROPELLER
SPIDER HUB SERVO PISTON (DOME)
OIL TRANSFER SLEEVE
FEATHERING SPRING BLADE ACTUATING LEVER
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.5
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER GOVERNOR GOVERNING MODE Description: Is the range of operation where engine power is sufficient to maintain the selected propeller speed by varying the blade angle (pitch). The System Is In The Governing Mode When: - Indicated propeller speed matches selected NP. - increase in Ng speed do not affect Np. - Moving the propeller lever results in a change in Np Components: Pressure Relief Valve: - Opens to bypass oil when maximum pressure is reached (450 to 720 depending on the model) Pump Gears: - Supply oil pressure to control the propeller pitch Governor Flyweights: - Rotation of the flyweights generate a centrifugal force proportional to the propeller speed - Flyweight force pushes against a spring to move the control valve up or down Pilot Valve: - Moves up and down under the influence of the flyweights - Controls the oil pressure going to the propeller
PT6A-60 SERIES
Speeder Spring: - Opposes a mechanical force to the centrifugal force of the flyweights - Determines the propeller speed at which the flyweights will be "on speed." - The pilot controls spring tension through the propeller lever (not on A-67B/P). Operation: Oil is supplied to the governor. A gear pump, mounted at the base of the governor, increases the flow of oil going to the CSU relief valve. When the oil pressure reaches the desired level, the relief valve opens to maintain the pressure. When the speed selected by the pilot is reached, the flyweights force equals the spring tension of the speeder spring. The governor flyweights are then on speed. When the engine output power is increased, the power turbines tend to speed up. The flyweights in the CSU sense this acceleration. The flyweights go into an overspeed condition because of the increase centrifugal force and force the control valve to move up and restrict oil flow to the propeller dome. The feathering spring increases the propeller pitch to maintain the selected speed. Reducing power causes an under-speed of the flyweights, downward movement of the control valve, more oil in propeller dome, resulting in a finer pitch to control propeller speed. The propeller governor houses an electro-magnetic coil, which is used to match the rpm of both propellers during cruise. An aircraft supplied synchro-phaser unit controls this function.
TRAINING USE ONLY
PROPELLER SYSTEM 11.6
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
GOVERNING MODE
NO MOVEMENT
RESET POST
PROPELLER SPEED CONTROL LEVER
BETA VALVE LEVER
GOVERNOR PRESSURE SPRING RELIEF SHUT-OFF VALVE (LOCK PITCH) SOLENOID VALVE
Py
RESET ARM
NO MOVEMENT
MIN. GOV. ADJ. ENGINE OIL
PILOT VALVE CSU PUMP
PT6A-67B/P WITH FIXED PROPELLER SPEED
BETA VALVE
SUPPLY PRESSURE RETURN TO PUMP PROPELLER SERVO PRESSURE
CARBON BLOCK NO MOVEMENT
BETA ROD HYDRAULIC LOW PITCH ADJ.
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.7
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER GOVERNOR BETA MODE (FORWARD OPERATION)
Power Lever:
Description:
On the ground, movement of the power lever below the idle gate causes the reversing cam to actuate the beta valve, thus causing the blade angle to reduce
The beta mode corresponds to a range of operation where the blade angle is between PBA (Primary Blade Angle) and reverse. The propeller pitch is a direct function of the beta valve position (power lever)
Function: - Prevents the blade angle from going below minimum in flight (Primary Blade Angle, PBA) - Allows the pilot to manually control the blade angle on the ground for taxiing and reverse operation
You Are In The Beta Mode When: - Indicated Np is below selected Np - A change in Ng speed causes a Np change - Propeller lever movement does not change Np
Beta Feedback System: In low pitch operation, the beta nuts, beta rods, slip ring, carbon block and the beta lever, which compose the beta feedback system, actuate the beta valve
PT6A-60 SERIES
Operation: At low power, the propeller and governor flyweights do not turn fast enough to compress the speeder spring. In this condition, the control valve moves down and high pressure oil pushes the dome forward, moving the blades towards a finer pitch. The propeller dome in it's forward movement contacts the beta nuts. Any further movement pulls the beta rod and the slip ring forward. The forward motion of the slip ring is transmitted to the beta valve via the beta lever and the carbon block. Forward movement of the beta valve stops the oil supply to the propeller. This prevents the blade angles from going any finer. This is called "Primary Blade Angle" (PBA) and it is the minimum blade angle allowed for flight operation. From this point the propeller is in the beta mode. If the engine power is reduced when the propeller is at the primary blade angle, the propeller speed will decrease since the blade angle does not change.
TRAINING USE ONLY
PROPELLER SYSTEM 11.8
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BETA MODE (FORWARD OPERATION) NO MOVEMENT
RESET POST
PROPELLER SPEED CONTROL LEVER
BETA VALVE LEVER
GOVERNOR SPRING
SHUT-OFF (LOCK PITCH) SOLENOID VALVE
Py
RESET ARM MOVES IN RESPONSE TO BETA FEEDBACK RING
MIN. GOV. ADJ. ENGINE OIL
PILOT VALVE CSU PUMP
BETA VALVE CARBON BLOCK
SUPPLY PRESSURE RETURN TO PUMP PROPELLER SERVO PRESSURE BETA FEEDBACK RING MOVES FORWARD AS PROP REACHES ≈ 10˚ PT6A-60 SERIES
TRAINING USE ONLY
BETA ROD HYDRAULIC LOW PITCH ADJ.
PROPELLER SYSTEM 11.9
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER GOVERNOR (CONT’D) Lockpitch Solenoid Valve: Prevents the propeller from going into reverse or below the primary blade angle in the event of a Beta system malfunction in flight. The solenoid is energized by a switch (airframe supplied) mechanically connected to the propeller slip-ring linkage via a second carbon block. Any movement of the slip ring towards reverse blade angle, prior to the pilot selecting reverse, energizes the solenoid and stops the oil flow from the governor pump to the propeller servo. This controls the blade angle from going any finer. As oil pressure leaks off around the propeller shaft oil transfer sleeve, the blade angle slowly drifts back toward coarse pitch. This will de-activate the low pitch solenoid valve and restore the oil supply to the propeller servo. The low pitch solenoid valve will cycle (close/open) as back-up to the beta valve function.
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.10
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BLANK PAGE
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.11
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER GOVERNOR BETA MODE (REVERSE OPERATION) Function: Allows the pilot to control the propeller with a negative blade angle. (Reverse thrust).
Operation: Moving the power lever backwards causes the reversing cam and cable to move the beta valve backward, allowing more oil to flow into the propeller dome, causing the blades to go towards reverse pitch. As the blades move to reverse, the slip ring is pulled forward by the dome (beta nuts) and moves the beta valve outward restricting the oil flow. This stops the blade movement toward reverse. To obtain more reverse thrust, the power lever must be moved back more to reset the beta valve inward and repeat the process.
As Np increases due to the increase in engine power, the governor flyweights begin to move outwards. Since the reset lever is closer to the speeder spring cup, the cup contacts the reset lever before the flyweights would normally reach the on-speed position (95% Np instead of 100%). When the reset lever is pushed up by the flyweights/ speeder spring cup, Py bleeds from the Fuel Control Unit (FCU) which lowers the Wf, engine power and thus propeller speed. In reverse Np remains 5% below the selected propeller speed so that the control valve remains fully open and only the beta valve controls the oil flow to the propeller dome. In this mode, the propeller speed is no longer controlled by changing the blade angle ( i.e.: servo pressure). It is now controlled by limiting engine power (i.e.: Ng speed).
The reset arm on the CSU is moved rearward by the interconnecting rod at the same time as the blade angle is moving toward reverse. This causes the reset lever and reset post to move down in the CSU. This brings the reset lever closer to the speeder spring cup.
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.12
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BETA MODE (REVERSE OPERATION) REVERSING CAM PUSH-PULL CONTROL
REARWARD MOVEMENT
PROPELLER SPEED CONTROL LEVER
BETA VALVE LEVER
RESET POST GOVERNOR SPRING Py
SHUT-OFF (LOCK PITCH) SOLENOID VALVE
RESET ARM
REARWARD MOVEMENT FCU ARM
UNDERSPEED ECCENTRIC SCREW
PILOT VALVE
BETA VALVE CARBON BLOCK
CSU PUMP ENGINE OIL
SUPPLY PRESSURE RETURN TO PUMP PROPELLER SERVO PRESSURE BETA ROD
FULL FWD POSITION
PT6A-60 SERIES
TRAINING USE ONLY
HYDRAULIC LOW PITCH ADJ.
PROPELLER SYSTEM 11.13
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER FEATHERING Function:
Maintenance:
Minimise propeller drag by streamlining the blades in the event of an in-flight engine shutdown.
Check feathering operation as per Airframe Maintenance Manual instruction. Adjustment:
Description: Bringing the propeller lever to the feather position causes the speed selection lever on the CSU to push the feathering valve plunger and allows propeller servo oil to dump into the reduction gearbox sump.
Adj. Feather screw CW -> Increases the time to feather Adj. Feather screw CCW->Decreases the time to feather
The pressure loss in the propeller hub causes the feathering spring and the propeller counterweights to feather the propeller quickly.
Note: The A-67B/P propeller governor has no provision for speed control. Feathering is done through a feather solenoid located on the propeller overspeed governor. The A-64 propeller governor has no feathering valve. Feathering is done through physically lifting the control valve by rotating propeller speed actuating lever completely CCW.
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.14
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER FEATHERING FEATHERING VALVE
SPEEDER SPRING ACTUATING LEVER GOVERNOR SPRING Py
TO SUMP
FEATHERING PLUNGER
TO SUMP
PILOT VALVE CARBON BLOCK
GOVERNOR OIL PRESSURE BYPASS TO PUMP PROPELLER SERVO PRESSURE BETA ROD HYDRAULIC LOW PITCH ADJ. PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.15
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NF GOVERNOR (OVERSPEED PROTECTION) Description: The CSU contains a Py bleed orifice closed by a ‘flapper’ valve and reset lever. The ‘flapper’ valve/reset lever can be opened by the speeder spring cup when the flyweights react to an increase in centrifugal force caused by an overspeed of the propeller/power turbines.
In Forward Propeller Operation: Provides Np overspeed protection (6% above selected prop speed) by bleeding-off Py air pressure from the FCU thus reducing the power of the engine.
The movement of the reset lever around its pivot point opens the Py air passage. Py bleeds into the reduction gearbox limiting the fuel supply to the engine. This will prevent the propeller/power turbines from accelerating beyond 106%.
Maintenance: - Adjust speed limit in reverse using the underspeed eccentric screw (max rev screw). - Over-speed limit adjustment in forward propeller operation is not permitted. - Check for Py leakage which will cause a loss of performance.
In Reverse Propeller Operation: Limits propeller speed to a value approximately 5% below the selected Np by bleeding-off Py air pressure from the FCU thus reducing the power of the engine.
Operation: In the event of a propeller overspeed not controlled by the propeller overspeed governor (oil governor), the flyweights in the propeller governor will move outwards until the speeder spring cup contacts the reset lever.
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.16
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NF GOVERNOR
RESET LEVER Py SEAL SPEEDER SPRING CUP FLYWEIGHTS Py
AIR BLEED ORIFICE PIVOT
Py AIR FROM FCU OIL TO RGB PROPELLER SERVO OIL PT6A-60 SERIES
TO SUMP
TRAINING USE ONLY
PROPELLER SYSTEM 11.17
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER OVERSPEED GOVERNOR increase in blade pitch puts more load on the engine and slows down the propeller.
(AIRFRAME OPTION) Function: Provides back up protection against propeller and power turbine over speeds (4% over max prop speed).
Description: - Airframe supplied except on A-67B/P - Flyweight governor actuating a control valve - One solenoid valve to reset the unit during ground tests - One solenoid to feather the propeller On the PT6A-67B, the overspeed governor feather solenoid is the only way to feather the propeller and the speed reset solenoid is replaced with a mechanical reset lever mounted on the governor.
Operation: The governor houses a set of flyweight connected to a control valve that is driven by a bevel gear mounted on the propeller shaft. The flyweight's centrifugal force is acting against two springs, a speeder spring and a reset spring.
To test the unit, the speed reset solenoid is activated and servo oil pressure pushes against the reset piston to cancel the effect of the reset spring. With less spring tension acting on the flyweights, the overspeed governor can be tested at speeds lower than maximum. On twin installation, a second solenoid valve is mounted on the overspeed governor and is used in conjunction with the aircraft auto-feather system. The system is switched on for take off and in the event of an engine malfunction will energize the solenoid valve to dump propeller servo oil into the reduction gearbox sump. The feathering spring and propeller counter-weights move the blade quickly to feather.
Maintenance: - Test the unit on a regular basis. - With the reset solenoid energized, verify the speed at which the overspeed governor controls Np. A67B/P: No solenoid, rotate mechanical reset lever to test - Refer to the Airframe Maintenance Manual for adjustment.
When the propeller speed reaches a specified limit (4% over maximum Np) the governor flyweights lift the control valve and bleed off propeller servo oil into the reduction gearbox sump, causing the blade angle to increase. An
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.18
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER OVERSPEED GOVERNOR (AIRFRAME)
SPEED ADJUSTING SCREW
RESET SPRING
REDUCES SPRING TENSION = LOWER O/S
RESET PISTON SPEEDER SPRING
FLYWEIGHTS
SPEED RESET SOLENOID
FEATHERING SOLENOID VALVE
SPEED RESET OIL ACTIVATION
GOVERNOR SPLINE DRIVE
FROM CSU
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.19
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NOTES
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.20
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER OVERSPEED GOVERNOR PT6A-67B OIL OUT FROM FEATHERING VALVE Py TO FCU ISOLATING SOLENOID VALVE
TQ LIMITER
PROPELLER OVERSPEED GOVERNOR (A-67B/P ONLY)
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.21
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER GOVERNOR ADJUSTMENTS
Maximum Forward Propeller Speed (Np)
-
Set propeller lever at maximum position in the cockpit Ensure that max Np stop is contacted Adjust screw CCW to increase maximum Np, CW to decrease. One flat alter Np 2% (A-67R/AF/AG), 4% (A-67/67A)
Maximum Reverse Propeller Speed
-
Set propeller lever at maximum Np position Disconnect reset arm from interconnect rod Secure reset arm against rear stop Move power lever forward until propeller speed stabilises Check that propeller speed stabilises within specified limits Adjust underspeed eccentric screw if required In some cases the FCU may not be adjusted to provide enough reverse power, this requires an initial check/adjustment of the FCU before adjusting the CSU
Feathering Operation Check
- Set power lever at ground idle - Move propeller lever to the feather position note feathering time, adj. as req.
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.22
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER GOVERNOR ADJUSTMENT
RESET ARM MAX. STOP DO NOT ADJUST
FEATHERING TIME ADJUSTMENT
A67B/P
FRONT CLEVIS
MAX PROP SPEED (FORWARD) TO CAM BOX
BETA LEVER BETA VALVE
UNDERSPEED ECCENTRIC SCREW (MAX REVERSE Np)
CAP NUT
INTERCONNECT ROD RIG FLUSH
VALVE
CLEVIS
BETA VALVE PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.23
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PRIMARY BLADE ANGLE (PBA) CHECK Function: Provide equal flight idle torques for appropriate aircraft handling. On twin engine applications the aircraft may yaw if PBA is not the same on both engines. On single engine aircraft, approach handling characteristics are dependant on PBA. Procedure:* - Record OAT - Record field barometric pressure - Set propeller lever at maximum position - Increase power until target Np is reached - Target Np speed is always less than maximum speed to ensure the beta valve is actuated - Stabilise engine and record torque - Compare indicated torque with torque given by chart in Airframe Maintenance Manual
Troubleshooting: - Indicated torque lower than target = PBA too fine - Indicated torque higher than target = PBA too coarse Adjust the beta valve position by adjusting the reversing cable clevis end - Move clevis end forward to increase torque - Move clevis end rearward to decrease torque Adjust beta nuts as per airframe manual to rectify - Move beta nuts rearward to increase torque - Move beta nuts forward to decrease torque Note: Some airframe or propeller manufacturers do not allow adjusting the beta nuts . The only option left is to adjust the beta valve inwards only . This will give a finer PBA on the higher indicating engine .
*(For reference only, refer to aircraft maintenance manual for specific procedure)
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.24
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PRIMARY BLADE ANGLE CHART
12000
10000
8000
6000
4000
2000
0
- 2000
- 4000
PRESSURE ALTITUDE IN FEET
40 30 20 10 OAT °C
0 -10 -20 -30 -40 900
300
600
PROPELLER TORQUE IN FT-LBS
PT6A-60 SERIES
TRAINING USE ONLY
0
PROPELLER SPEED 1500 RPM PROPELLER SYSTEM 11.25
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PROPELLER SYSTEM TROUBLESHOOTING Observed Problem
Action Required
Np And Torque Fluctuations At High Power (No Ng Fluctuation)
Max Np setting may be too high (interference with OSG) Overspeed governor test solenoid leaking. (interferes with prop.Governor)
Np And Torque Fluctuation At Low Power (In Beta)
Verify Beta ring is not distorted Inspect carbon block for excessive wear Check beta nut adjustment (not equal)
Propeller Slow To Unfeather
Carbon block worn out or beta valve rigged too far out Low servo pressure from prop. governor
Np, Tq And Ng Fluctuation (Power Fluctuation)
Ensure reset arm is positively sitting against forward stop Verify Py line for leaks Replace FCU if problem is still present
Propeller Rpm Too High (Governing)
Check propeller speed gauge for accuracy Adjust maximum stop on governor Replace prop. governor if adjustment is not effective
Propeller Rpm Too Low (Governing)
Insure max stop is contacted Adjust maximum stop on governor Ensure Ng is not limited by any P3 or Py leak. Replace propeller governor Check/Replace overspeed governor
Propeller Rpm Too Low (Reverse)
Check Nf governor minimum adjustment in reverse Adjust FCU maximum reverse Ng stop
Propeller Rpm Too High (Reverse)
Check that maximum forward propeller speed is OK Check proper rigging of the reset arm. May not be bleeding enough Py Check Nf governor minimum adjustment in reverse
PT6A-60 SERIES
TRAINING USE ONLY
PROPELLER SYSTEM 11.26
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
MAINTENANCE PRACTICES
MAINTENANCE PRACTICES
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.1
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERIODIC INSPECTION The following table is for reference only, refer to your Engine Maintenance Manual. Routine : coincides with daily or pre-flight airframe inspection. Minor : coincides with a typical airframe inspection. Notes: 1)The intervals at which these inspections are performed may be altered by the aircraft manufacturer’s maintenance program and approved by the operator’s local airworthiness authority. 2)Engines operating in sandy or dusty environments or in smog or salt-laden atmospheres should be subjected to additional inspections for corrosion and compressor erosion.
FREQUENCY
COMPONENTS
25 hours
2nd Power Turbine Blades
50 hours
2nd Stage PT Blades
100 hours
Engine Oil Oil Filter Element AGB Drive P3 Air Filter P3 Air Filter Drain Valve Chip Detector
125 hours
2nd Power Turbine Blades
Minor
Control Linkage
FREQUENCY
COMPONENTS
Fuel Control Unit
Routine
Oil Level
Manual Override FCU
Oil Filler Cap
Fuel Pump
Fuel System
Fuel Pump Outlet Filter
Fuel & Oil Lines
Oil-to Fuel Heater
Scavenge Oil Pump Housing
P3 Air Filter
Propeller Oil Shaft Seal
P3 Air Filter Bowl
Accessories
Oil Filter Element
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.2
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
PERIODIC INSPECTION (CON’T) FREQUENCY
COMPONENTS
FREQUENCY
COMPONENTS
Minor
Tubing, Wiring & Hoses (Oil/Fuel/P3/Py)
250 hours
2nd Power Turbine Blades
300 hours
Fuel Pump Inlet Screen
Ignition Exciter
Oil Filter
Ignition Cables Sparks Igniters
400 or 600 hours
Fuel Manifold Adapter & Nozzle Assemblies
600 hours
Sundstrand Fuel Pump only
Accessories Air Inlet Screen
Fuel Pump Inlet Screen
Air Inlet Case
Fuel Pump Outlet Filter
Gas Generator Case
600 hours or 12 months
Chip Detector
Fireseal Mount Rings
1,000 hours
Oil Filter
Drain Valves
Agb Scavenge Pump Filter
Flow Divider
P3 Air Filter
Exhaust Duct 200 hours
2nd Power Turbine Blades
At component Replacement / Removal
Accessory Gearshaft Spline
Fuel Manifold Adapter & Nozzle Assemblies 200 hours or 6 months
AGB Scavenge Pump Filter
200 or 400 hours
Fuel Manifold Adapter & Nozzle Assemblies
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.3
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION INSPECTION Purpose: To optimize engine performance, fuel economy, safety and increase components life. The condition of the hot section parts has a direct effect on engine performance. Deterioration of the hot section can be detected by using engine condition trend monitoring (ECTM) and / or by doing performance checks (refer to chapter 9). Deterioration of hot section components may include cracking, burning, buckling, erosion, fretting wear and corrosion. Hot section distresses is usually attributed to malfunctioning fuel nozzles, hot starts, running the engine beyond acceptable ITT limits, continuous operation at maximum power, doing rapid accelerations, or abusing reverse thrust or FOD.
Goals Of The HSI Include: - Maintaining CT blade tip clearance close to a minimum - Optimizing lug to slot fits on CT vane - Minimizing P3 air leaks, internal or external - Ensuring that replacement compressor turbine vane ring and power turbine vane ring classes are kept the same as installed during the last test-cell run.
PT6A-60 SERIES
HSI Frequency: - As per relevant SB - On condition (as per ECTM result) Pre HSI Actions: 1. Do a performance check. The result of the performance check will be compared with a post HSI check to monitor performance recovery. 2. Remove and inspect oil filter, magnetic chip detector and RGB strainer for metal contamination. 3. Remove air inlet screen and inspect first stage compressor blades for F.O.D. Return engine to an overhaul facility if #2 check is beyond limits. Engine Disassembly: - Remove power section - Measure Compressor Turbine blade tip clearance - Remove Compressor Turbine assembly - Remove fuel nozzles - Remove spark igniters - Remove combustion chamber liners - Remove CT vane assemble - Remove large exit duct
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.4
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NOTES
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.5
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
BORESCOPE INSPECTION Description: The borescope inspection allows operators to visually inspect hot section components without disassembling the engine.
Procedure: - Remove one fuel manifold adapter. - Insert the guide tube through the open port. - Install the holding fixture to the engine "C" flange. - Connect the borescope to the light source. - Insert the borescope into the guide tube with care.
The following components can be inspected with a borescope: - Compressor turbine blades. - Leading and trailing edges of compressor turbine vane ring. Inner and outer walls of vane rings. - All CT vanes can be inspected when fuel nozzles are removed for inspection. - Turbine shroud segments. - Cooling rings and dome section of the combustion chamber.
Note: Keep in mind that you are looking 125 degrees away from the point of entry of the tip as shown in the figure.
Use the borescope with care since it is a very fragile device.
A 35-mm, digital or a video camera may be mounted on the viewer to record inspection of hot section areas (adapters required).
All compressor turbine blades can be inspected through one fuel nozzle adapter port. Using the proper tool in the starter drive can rotate the compressor. Ensure borescope tip does not interfere with compressor turbine blades. The guide tube is not required for the inspection of combustion chamber liner.
Engine must be cool prior to using the borescope. Cool down engine for a minimum of 40 minutes.
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.6
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
GUIDE TUBE ORIENTATION
FUEL MANIFOLD ADAPTER PORT RIGID GUIDE TUBE
POINT OF ENTRY (REF.)
FIBERSCOPE TIP 125 VANE RING DISTAL POINT RELATION BETWEEN POINT OF ENTRY AND DISTAL TIP
VIEW FROM EXHAUST DUCT TOWARD AIR INLET CASE PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.7
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION TOOLS 1. Power Section Sling (Without The Propeller Installed On The Engine) (PWC34673). 2. Compressor Turbine Holding Wrench (PWC30331). 3. Spacers (4) (PWC34478). 4. Spreader (PWC30335). 5. Compressor Turbine Puller (PWC30403). 6. Protector Sleeve (PWC30336). 7. Puller No. 2 Bearing Cover (PWC32823). 8. Dial Indicator (PWC 32280). 9. Shroud Grinder Adapter (PWC 32209). 10. Fuel Nozzle (PWC32811). 11. Grinder (PWC37918). 12. Crimper (PWC30458).
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.8
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION TOOLS
PT6A-60 SERIES
7
2
10
4
5
6
3
8
9
1
11
12
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.9
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
CT TIP CLEARANCE MEASUREMENT Procedure: - Measure tip clearance using a tapered or a wire feeler gage, loading the CT disk in the direction of the measurement. - The tip clearance limits for each individual model is listed in the Engine Maintenance Manual. - No need to rotate turbine while taking measurements.
Limits Shown In The Maintenance Manual: - Average clearance for new segments. - Average clearance for used segment (that ran at least 5 minutes at take off power).
Amount Of Readings Taken: - Average all readings and compare with limits stated in Engine Maintenance Manual. - For 10 segment types, take 3 readings per segment. (3 readings x 10 segments = 30 readings). - For 20 segment types, take 2 readings per segment. (2 readings X 20 segments = 40 readings)
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.10
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NOTES
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.11
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION INSPECTION (CONT’D) Inspection Gas Generator Case: - Inspect case for cracks, distortion, corrosion and evidence of overheating. - Inspect engine mount threads. - Inspect P3 air supply holes at CT vane flange for blockage. - Inspect diffuser pipes for cracks and fretting wear. - Inspect shanknuts at CT vane flange for security.
Combustion Chamber Liners: - Visually inspect the liners for evidence of burning, cracking, buckling or metal to metal fretting wear. - Regap cooling rings if they are distorted. - Stop drilling of cracks and welding may be required (refer M/M for limits).
Small Exit Duct: - Inspect for evidence of burning, cracking, buckling, coating loss or metal to metal fretting wear. - Stop drilling of cracks may be required (refer M/M for limits)
PT6A-60 SERIES
CT Vane: - Inspect vane ring for evidence of burning, cracking and coating loss. - Insure proper sliding fit (lugs to slots) with mating parts. - Check air-cooling holes for blockage. - Change ‘C’ & ‘W’ seal rings.
Shroud Housing: - Inspect shroud housing for cracks, blockage of cooling air holes, fretting wear at sealing ring contact area
Shroud Segments: - Inspect shroud segments for cracks, burning distortion and metal buildup - Tip clearance
Compressor Turbine: - Inspect CT blades for: tip rub, cracks, sulphidation, erosion, burning and coating loss. - Inspect CT disk for damage. - Wash turbine blades based on past sulphidation experience.
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.12
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
CT BLADE SULPHIDATION
STAGE 1 - MILD SULPHIDATION
STAGE 2 - OXIDE FAILURE
EVIDENT SLIGHT ROUGHNESS OF SURFACE DUE TO SOME GROWTH AND BREAK DOWN OF THE OXIDE LAYER. DEPLETION OF CHROMIUM HAS NOT STARTED. MECHANICAL INTEGRITY IS NOT AFFECTED
ROUGHNESS OF SURFACE IS MORE EVIDENT AS BREAKDOWN OF THE OXIDE SCALE LAYER CONTINUES. DEPLETION OF CHROMIUM FROM UNDERLYING ALLOY HAS STARTED. MECHANICAL INTEGRITY STILL NOT AFFECTED.
STAGE 3 - SEVERE SULPHIDATION
STAGE 4 - CATASTROPHIC ATTACK
OXIDATION OF THE BASE MATERIAL HAS PENETRATED TO SIGNICANT DEPTH. BUILD-UP OF BLISTER SCALE NOTICEABLE. MECHANICAL INTEGRITY SERIOUSLY AFFECTED.
DEEP PENETRATION OF SULPHIDATION ATTACK WITH LARGE BLISTER OF SCALE. LOSS OF STRUCTURAL MATERIAL LIKELY TO RESULT IN BLADE FRACTURE.
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.13
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION INSPECTION (CONT’D) Inter-Stage Sealing Ring: - Inspect sealing ring(s) for fretting wear on sealing diameter and face. - Fit ring on sealing diameter for full contact.
Sealing surface restoration Purpose: To achieve best sealing of P3 in the gas generator case area and keep leakage to a minimum.
Power Turbine Vane: - Inspect vane ring for evidence of burning, cracking and coating loss. - Ensure proper sliding fit (lugs to slots) with PT stator housing. - Damage to the power turbine vane ring is not common unless bad fuel nozzles caused damage to CT area.
Description: There are 2 sealing surface contacts that must be checked for proper seating:
Power Turbines: - Inspect the 1st and 2nd stage power turbines for: cracks, burning, coating loss, corrosion, and impact damage and blade shift. - Return the power section to an authorized overhaul facility if either turbine needs to be replaced.
Gas tight contact between these surfaces, depends on surface finish and flatness. Surface finish should be better than 32 micro-inches and .0005" max waviness. Lapping can be used to eliminate minor surface imperfections. When lapping is impractical, the assemblies should be machined at an approved overhaul facility.
1. Lock-plate to vane ring inner diameter. 2. Vane ring outer diameter to small exit duct.
Exhaust Case: - Inspect the case for general condition. - Check the case for cracks near the flanges. - Inspect flange -D- area for cracks around PT shroud.
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.14
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION INSPECTION (CONT’D) Fitting Of Hot Section Parts
Step 2:
Purpose: - To achieve best fitting of the hot section parts for minimizing side play which can result in CT tip rub. - To allow thermal expansion to take place, without any binding.
Install the shroud housing on a bench with the slots uppermost. Install the vane ring lugs inside the shroud housing lugs.
Description: There are 2 lug to slot fit areas that must be checked for proper fit: 1. Vane ring inner lugs to #2 bearing cover slots. 2. Vane ring outer lugs to shroud housing slots.
Rotate the vane in the direction it would want to turn, as the gases flow through it. Hold the shroud housing still. This will force the lugs to contact the slots on one side and to have a loose fit on the other side. Measure clearance on both sides with a narrow feeler gage, ref. MM for limits. If clearance cannot be achieved, re-index the parts and measure. If clearance can still not be obtained, remove material lightly with a stone until fit is achieved.
Step 1: Install the vane ring on a bench with the inner lugs uppermost. Install the #2 bearing cover slots around the vane ring lugs. Rotate the vane in the direction it would want to turn, as the gas flow through it. Hold the #2 bearing cover still. This will force the lugs to contact the slots on one side and to have a loose fit on the other side. Measure clearance on both sides with a narrow feeler gage, ref. MM for limits.
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.15
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION INSPECTION (CONT’D) Shroud Segment Grinding To achieve optimum Compressor Turbine tip clearance all around the shroud.
Hot Section Kit: Operators who are equipped with the proper tooling can do their own grinding. The preferred method is to send the hot section kit to an approved P&WC service center, which can achieve a superior surface finish and concentricity control. The hot section kit consists of the following: - CT vane assembly (vane ring, small exit duct, shroud housing and segments. - #2 bearing cover and / or flange. - Lockplate. - Compressor turbine assembly.
Preparations: - Mask vane ring, #2 bearing and gas generator area carefully. - Install the 4 rubber spacers with equal tension between the large and small exit ducts. - Install the grinder adapter on compressor stub shaft. - Install the radius gage on the adapter and calculate the tip clearance.
Calculating Amount Of Metal Removed By Grinding The shroud inside dimension (radius) is measured by comparing reference master tool to the shroud dimension. The dimension stamped on the master tool is the radius from the center of the gage to the step on the master tool. Set gage dial to zero when it is on the master.
Grinding can be minimized by carefully selecting classes to compensate for ovality or eccentricity of the shroud housing. The best fitting class segments is picked after measuring the CT outside diameter and referring to a table from the Engine Maintenance Manual. It is recommended to go 1class higher (thicker segments) to offset any excessive ovality from the shroud housing.
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.16
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION INSPECTION (CONT’D) Calculate Actual Tip Clearance Before Grinding As Follows: (the numbers used are for examples only) - Dimension stamped on side of - gauge (master).= 4.282" - Dial gage reading.= -0.009" (plus or minus sign is important) - CT largest diameter / 2 (8.532 / 2).= 4.266" Step 1 = Find the radius of the shroud: (master + dial reading => 4.282" -.009")= 4.273" Step 2 = Find actual CT tip clearance: (shroud radius - disk radius => 4.273" - 4.266") = 0.007" Step 3 = Determine material to be removed, assuming required tip clearance is .010". (actual clearance - required clearance : .007" - .010")
= -.003"
We need to grind .003" off the segments. Note: Refer to Maintenance Manual for proper grinding procedure.
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.17
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION INSPECTION (CONT’D) Fuel Nozzle Functional Check: Ensures the engine combustion chamber receives properly atomized fuel.
Inspection Interval: - 200 hours for new operators. - 400 hours max interval afterwards, depending of condition.
Spray Pattern Check: - Flow test for spray pattern at 20 PSI. Check for drooling and spitting (none permitted). - There may be an onion or tulip shaped spray pattern. - Flow test for spray pattern at 60 PSI. Check for spray pattern streakiness, drooling or spitting. - 20% max streakiness is allowed
Note 1: All values are for reference only. Always refer to the appropriate Maintenance Manual for proper settings.
Pressure Test: Pressure test for leakage between nozzle tip and adapter at 500 PSIG fluid pressure or 200 PSIG air pressure, no leakage allowed.
Fuel Nozzle Cleaning: - When spraying, brush tip with a non-metallic brush to loosen any possible carbon debris. - If above method is not effective, ultrasonically clean nozzles in carbon remover solvent. - Always rinse nozzles in hot water after cleaning, since carbon solvent is corrosive.
Fuel Nozzle Sheaths: - Inspect sheaths for erosion on the dome top. - Inspect sheaths for wear at combustion chamber contact area. - Check gap between sheath and adapter flange. - Check concentricity between sheath and adapter orifice with a .020" drill.
Note 2: If a streaking nozzle is found during testing, a visual HSI or borescope inspection of the hot section should be done.
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.18
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
HOT SECTION INSPECTION (CONT’D) T5 System Functional Check:
Heat Response Test: (T5 Probe Functional Check)
T5 system inspection should be performed during hot section inspection with the engine split at flange "C" or whenever a T5 indication problem is suspected.
This check is done to verify proper functioning of T5 probes. Ensures T5 probes respond to heat. With engine split at "C" flange, connect test set to alumel and chromel lead. Heat each probe individually and verify response. Replace faulty thermocouple probe.
Continuity Resistance (Loop) Check: Ensures continuity and proper resistance in the T5 probes, bus-bars, wires and terminals. Disconnect all leads from T5 terminal block on gas generator case (use care, while disconnecting leads, to avoid cracking the insulation material) and measure resistance between Alumel and Chromel terminals. Disconnect T5 probes from bus-bar and measure resistance between Alumel and Chromel terminals, refer to Maintenance Manual for resistance limits.
Note: - Each T5 probe can be checked for loop and insulation resistance if a fault is suspected. - Always clean connector carefully to ensure resistance of the system is not disturbed
Trim Thermocouple Check: This check is done to ensure proper resistance of the trim stick.
Insulation (Ground) Resistance Check: This check is done to ensure system is not grounded (shorted). Ensures that neither Alumel nor Chromel bus bars are contacting the casing. Connect test set between alumel or chromel and ground (gas generator case) and measure insulation resistance. Minimum resistance must not be less than specified limit.
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.19
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
NOTES
PT6A-60 SERIES
TRAINING USE ONLY
MAINTENANCE PRACTICES 12.20
P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface
RIGGING
RIGGING
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.1
BASIC ENGINE RIGGING Purpose: Provide the operator with a basic approach to engine rigging. This section defines the logical sequence that should be followed when rigging the engine. It also describes the post run-up adjustments necessary to get an ideal cockpit lever to engine response relationship. Use the airframe maintenance manual for specific engine rigging information.
COCKPIT LEVERS
CUT-OFF LEVER
Pre-Rigging Verification: - Ensure that cockpit levers and cables operate freely and do not bind before connecting it to the engine. - Ensure that the engine reversing cable is not damaged and operates freely when disconnected from the beta lever. - Verify that the propeller reversing lever is connected to the beta valve and make sure the carbon block is in good condition. - Verify that the beta valve is properly connected to the beta lever. - Verify run-out on beta feedback slip ring (.003 max) - Check that beta valve slides freely.
CAM BOX
CSU REVERSE LEVER
CSU SPEED LEVER
FCU LEVER
You are now ready to rig the engine.
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.2
REAR LINKAGE RIGGING One of the first steps prior to rigging the fuel control unit on the PT6 is to carefully rig the cambox position. Once this is done, the fuel control unit and the reversing cable can be rigged.
Note: A “rig pin" hole located on the cambox may be used to facilitate the track point rigging. Ensure that the above procedure applies for a more precise rigging.
Cambox Rigging: With the airframe power lever cable and the engine reverse cable disconnected from the cambox, move the cockpit power lever through the full range and verify motion is free of binding and excessive friction. - The next step is to find the track point. - Cycle the power lever forward and back slowly until the cockpit idle detent is contacted. - Find the track point by rotating the cambox input lever counterclockwise until the reverse cam moves back 1/ 32 inch (apply light forward force on reversing cam while measuring). - Once the track point is located, position the cambox input lever at the angle specified by the airframe manufacturer. - Cycle the cockpit power lever between maximum forward and reverse position and ensure the power lever cable terminal travel exceeds the required input l lever displacement. - Connect the airframe power lever cable to the cambox input lever
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.3
WOODWARD FUEL CONTROL RIGGING 1. Disconnect the FCU interconnecting rod and set it's length to 1/8 inch shorter than specified in the airframe maintenance manual (the rod length will be rectified later on). 2. With the rod disconnected position the fuel lever to contact the idle stop without going into the deadband. 3. Connect the FCU inter connecting rod to the proper hole on the FCU actuating lever. Connect the rear end of the rod to the FCU arm using the serrated washer to position the FCU shaft as marked in step 2 (at the idle stop). 4. Remove FCU interconnect rod and lengthen it 1/8 inch (so it goes back to airframe manual recommendation). This will provide some forward deadband (approximately 1/4 inch) on the pedestal before Ng picks up. 5. Move the power lever through the full range (make sure the reverse cable is disconnected). The cam follower pin should not bottom out at either end of the reverse cam slot. In the maximum forward position, the FCU maximum Ng stop screw should contact the FCU maximum stop.
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.4
REAR LINKAGE (WOODWARD) REVERSING CAM IDLE REVERSING CABLE
NUAL
IDLE
MA AME
IRFR
FORWARD
RA S PE
HT A
LENG REVERSE
CAMBOX INPUT LEVER
CAM FOLLOWER PIN
FCU CONNECTING ROD
FCU ARM
MAX FORWARD NG STOP DEAD-BAND ADJUSTMENT
CAM BOX
AIRFRAME POWER LEVER CABLE HIGH IDLE ROLLER HIGH IDLE CAM MAX REVERSE NG STOP PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.5
FRONT LINKAGE RIGGING Telescopic Interconnect Rod:
Rigid Interconnect Rod:
1. Disconnect the reverse cable at the cambox.
1. Disconnect the reverse cable at the cambox.
2. Move the Power Lever in the cockpit between Flight Idle and Max Power setting to verify free movement.
2. Move the cockpit power lever between idle and maximum power position to verify free movement
3. Pull on the Beta Lever and adjust the front clevis so that the Beta Valve clevis slot face is flush with the Beta Valve cap.
3. Disconnect the propeller governor interconnect rod, pull on the beta lever and adjust the front clevis so that the beta valve clevis slot face is flush with the beta valve nut.
4. Adjust the length of the interconnect rod to get the required gap as specified in the Airframe Maintenance manual.
4. Connect the reverse cable rear clevis to the required hole in the reverse cam. Adjust the clevis so that the cable is in light compression (pushed forward) when the clevis pin is installed.
5. Cycle the cockpit levers from idle to max power to verify smooth operation. Adjust the reverse cable pre-load at the rear clevis connection if excessive friction is observed. The reverse cable will be in tension since it is pushed forward by the Beta valve spring.
5. Connect the CSU interconnect rod in the specified holes and adjust it to get a sliding fit, then shorten thread by turning one end 1/2 turn. 6. Cycle the cockpit power lever from idle to maximum to confirm smooth motion. Adjust the reverse cable pre-load at the rear clevis connection if excessive friction is observed.
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.6
FRONT LINKAGE FEATHERING TIME ADJUSTMENT
RESET ARM MAX. STOP DO NOT ADJUST
FRONT CLEVIS
BETA LEVER
MAX PROP SPEED (FORWARD) TO CAM BOX
BETA VALVE
PNEUMATIC MINIMUM ADJUSTMENT (MAX REVERSE Np)
CAP NUT
INTERCONNECT ROD (GAP AS PER AIRFRAME M.M.)
RIG FLUSH
VALVE
BETA VALVE PT6A-60 SERIES
TRAINING USE ONLY
CLEVIS
RIGGING 13.7
FUEL CONDITION LEVER - Disconnect control cable from the fuel idle reset/cutoff lever - Insert rigging pin through the idle reset/cut-off lever - Place cockpit fuel condition lever to ground idle and adjust the aircraft cable to fit to the appropriate hole on the idle reset/cut-off lever - Remove rigging pin
Propeller Lever: - Move the cockpit propeller lever fully forward. Ensure that speed select lever contacts maximum Np stop screw. Adjust console stop to comply. - Move cockpit propeller lever to feather. Ensure speed select lever fully depresses the feathering valve plunger.
Ensure : - Fuel condition lever moves freely throughout the entire range
Note: Speed select levers should be loaded slightly against the maximum Np when maximum propeller speed is selected.
At Cut-Off Position : - Ensure that there is a positive contact with the cut-off stop. - Ensure that the unloading valve screw fully depresses the unloading valve plunger.
Post Rigging Check: Ensure the propeller feathers when the cockpit propeller lever is halfway through the feather detent.
At High Idle Position : - Ensure high idle stop is contacted Prior To Starting The Engine: - Disconnect the fuel line going to the flow divider - Perform a wet motoring run to confirm Positive fuel cut-off - Ensure cut-off happens when the fuel lever position is halfway through the cut-off detent. - Check low and high idle speed as per aircraft maintenance manual
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.8
FUEL & PROPELLER LEVER RIGGING FEATHER STOP SCREW MAX. SPEED ADJ.
RESET ARM MAX. STOP DO NOT ADJUST
FCU HIGH IDLE STOP (ONLY IF STAGGER EXISTS)
CUT-OFF STOP
WOODWARD
CSU
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.9
POST RUN UP ADJUSTMENTS Prior to running the engine ensure that: - The FCU maximum Ng stop is contacted when the cockpit power lever is advanced to the maximum position. - The cut-off stop is contacted when the condition lever is at the cut-off position. - The speed select lever on the CSU makes firm contact with the maximum speed stop.
Symptom
Fix
Idle Ng Too High
- Ensure rigging was done properly - Adjust Ng speed as per manual’s instructions
Idle Ng Too Low
- Ensure there are no P3 or Py leaks - Adjust as per manual instructions
Ng Pick-Up Point Is Different On The Two Engines (Constant Stagger)
Before adjusting make sure that: - The deadband is the same on the two engines - The power lever travel movement from idle to take off is the same on the two engines (stagger is constant). To Adjust: - To move the pick-up point forward on the quadrant, turn the serrated washer clockwise. (Do not change the rod length) NB: 2 teeth change on serrated washer = .040" movement on the cockpit quadrant approximately.
Unequal Power Lever Travel Movement From Idle To Take Off Between The Two Engines (Progressive Stagger)
Before adjusting - Ensure low and high idle speeds are the same on both engines - Ensure maximum Np is the same on both engines. To Adjust: - To shorten the power lever travel, (PLA ahead) shorten FCU interconnecting rod - Reposition the pick-up point by adjusting the serrated washer (counterclockwise in this case)
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.10
POST RUN UP ADJUSTMENTS (CONT’D)
Symptom
Fix
Primary Blade Angle Check; Different Torque On The Two Engines
- Verify position of the beta valve is identical on the two engines when the cockpit power lever is advanced halfway between idle and maximum power. - Adjust beta valve position using the reversing cable clevis end (small adjustment) or adjust beta nuts if airframe maintenance manual permits (big adjustment) - Send propeller to an overhaul shop if beta nuts adjustment is not allowed. Beta valve position has a limited effect on PBA.
Propeller Zero Pitch Position (Np Increase In Rearward Deadband) Is Staggered On The Two Engines
- Confirm the beta valve position is flush with the beta valve cap nut. - Ensure the reverse cable clevis is connected to the specified reverse cam hole. - Ensure the cambox track point is rigged the same on the two engines. - Perform primary blade angle check (Calibrate torque transducer). Adjust PBA as required
Pilot Reports YAW During Approach
- Verify track point rigging - Verify beta valve rigging - Perform primary blade angle check
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.11
TWIN ENGINE RIGGING TROUBLESHOOTING Condition 1
Ideal Condition.
May vary from airframe to airframe. The Airframe Maintenance manual provides a description of the required settings after engine rigging.
Condition 2 Ng Pick-Up And Target Points Are Split. - Displace the pick-up point with the serrated washer. This will also bring the power lever more or less in line. - Also the deadband must be adjusted.
Condition 3 Power Lever Stagger For Equal Torque - Correct the stagger by lengthening the FCU interconnecting rod on the right hand side engine. - This will move the pick-up point forward which can be corrected by adjusting the serrated washer on the right hand side engine.
Condition 4
Ng Pickup Point Split But Equal At Power. - Lengthen the FCU interconnect rod on the right hand side engine. - Adjust deadband screw (.003” gauge test) and the serrated washer to set the “deadband angle” and “pick-up point position” the same on both engines. - Start engine and verify the idle speed.
PT6A-60 SERIES
Condition 5 Reverse Pick-Up Point Are Split - Adjust deadband screw on the right hand engine (CCW) to reduce the band. This will change the deadband in forward as well. - Reposition the deadband using the serrated washer (.003” feeler gauge test). Start engine and re-adjust the idle speed.
Condition 6 Beta Valve Tracking Point Is Staggered (Np increases in Beta). - Verify the Cambox reverse “track point” is rigged correctly. - Verify “pre-loading” of pin connecting the reverse cam and the clevis.
Condition 7
Forward & Reverse Pick-Up Point Not Matched - Move deadband using serrated washer (but do not adjust angle) rearward on right engine - Use paper check to have both engines at same position
TRAINING USE ONLY
RIGGING 13.12
POST RUN-UP ADJUSTMENTS (TWIN ENGINE)
1 TQ
TQ
TQ
PU BVT
PU BVT
PU BVT
PU
PU
PU
INC
IDLE DETENT
P O
2
3 TQ
PU
4 TQ
TQ
TQ
TQ
PU
BVT
PU BVT
PU BVT
PU BVT
BVT
PU
PU
PU
PU
PU
W E
R IDLE
L I F T
5
IDLE L I F T
IDLE DETENT REVERSE
6
7
TQ
TQ
TQ
TQ
TQ
PU BVT
PU BVT
PU BVT
PU
PU BVT PU
PU
PU
PU
BVT PU
TQ
PU BVT PU
LEGEND TQ : CRUISE TORQUE PU : NG PICK -UP POINT Z T : ZERO THRUST POSITION BVT:BETA VALVE TRACKING
PT6A-60 SERIES
TRAINING USE ONLY
RIGGING 13.13
TRAINING MATERIAL CHANGE REQUEST
Date: ________________________________ Company Name and Address: ____________________________________________________________________________ Your Name: __________________________________
Job Title:_________________________________________
Training Aid Title:_______________________________________________________________________________________ Reference Page(s): _____________________________________________________________________________________ Recommended Change(s) and Reason(s) for Change(s):_______________________________________________________ _____________________________________________________________________________________________________ _____________________________________________________________________________________________________ ____________________________________________________________________________________________________ TMCR ID Number (P&WC Office Use Only): _________________________________________________________________ Send To: Pratt & Whitney Canada Customer Training 1000 Marie-Victorin (05CA1) Longueuil, Quebec, Canada, J4G 1A1 Email: [email protected]
PT6A-60 SERIES
Note: If you would like to be contacted regarding the resolution of your request for change, please provide us with your telefax number on the following line. Telefax Number: _________________________________
TRAINING USE ONLY
RIGGING 13.14
