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LEP 1 Jan 24/2006 2 Jan 24/2006 3 Jan 24/2006 4 Jan 24/2006 5 Jan 24/2006 6 Jan 24/2006 7 Jan 24/2006 8 Jan 24/2006 Contents 1 Jan 24/2006 2 Jan 24/2006 3 Jan 24/2006 4 Jan 24/2006 5 Jan 24/2006 6 Jan 24/2006 7 Jan 24/2006 8 Jan 24/2006 9 Jan 24/2006 10 Jan 24/2006 11 Jan 24/2006 12 blank Jan 24/2006 72-00-00 Description and Operation 1 Nov 04/2005 2 Nov 04/2005 3 Nov 04/2005 4 Nov 04/2005 5 Nov 04/2005 6 Nov 04/2005 7 Nov 04/2005 8 Nov 04/2005 9 Nov 04/2005 10 Nov 04/2005 11 Nov 04/2005 12 Nov 04/2005 13 Nov 04/2005 14 Nov 04/2005 15 Nov 04/2005 16 Nov 04/2005 17 Nov 04/2005 18 Nov 04/2005 19 Nov 04/2005 CHAPTER
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20 Nov 04/2005 21 Nov 04/2005 22 Nov 04/2005 23 Nov 04/2005 24 Nov 04/2005 25 Nov 04/2005 26 Nov 04/2005 27 Nov 04/2005 28 Nov 04/2005 29 Nov 04/2005 30 Nov 04/2005 31 Nov 04/2005 32 Nov 04/2005 33 Nov 04/2005 34 Nov 04/2005 35 Nov 04/2005 36 Nov 04/2005 37 Nov 04/2005 38 Nov 04/2005 39 Nov 04/2005 40 Nov 04/2005 41 Nov 04/2005 42 Nov 04/2005 43 Nov 04/2005 44 Nov 04/2005 45 Nov 04/2005 46 Nov 04/2005 47 Nov 04/2005 48 Nov 04/2005 49 Nov 04/2005 50 Nov 04/2005 51 Nov 04/2005 52 Nov 04/2005 53 Nov 04/2005 54 Nov 04/2005 55 Nov 04/2005 56 Nov 04/2005 57 Nov 04/2005 58 Nov 04/2005 59 Nov 04/2005 60 Nov 04/2005
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61 Nov 04/2005 62 Nov 04/2005 63 Nov 04/2005 64 Nov 04/2005 65 Nov 04/2005 66 Nov 04/2005 67 Nov 04/2005 68 Nov 04/2005 69 Nov 04/2005 70 Nov 04/2005 71 Nov 04/2005 72 Nov 04/2005 73 Nov 04/2005 74 Nov 04/2005 75 Nov 04/2005 76 Nov 04/2005 77 Nov 04/2005 78 Nov 04/2005 79 Nov 04/2005 80 Nov 04/2005 81 Nov 04/2005 82 Nov 04/2005 83 Nov 04/2005 84 Nov 04/2005 72-00-00 Fault Isolation 101 Sep 03/99 102 blank Sep 03/99 72-00-00 Maintenance Practices 201 Nov 04/2005 202 Nov 04/2005 203 Nov 04/2005 204 Nov 04/2005 205 Nov 04/2005 206 Nov 04/2005 207 Nov 04/2005 208 Nov 04/2005 209 Nov 04/2005 210 Nov 04/2005 211 Nov 04/2005 212 Nov 04/2005 213 Nov 04/2005 CHAPTER
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214 Nov 04/2005 215 Nov 04/2005 216 Nov 04/2005 217 Nov 04/2005 218 Nov 04/2005 219 Nov 04/2005 220 Nov 04/2005 221 Nov 04/2005 222 Nov 04/2005 223 Nov 04/2005 224 Nov 04/2005 225 Nov 04/2005 226 Nov 04/2005 227 Nov 04/2005 228 Nov 04/2005 229 Nov 04/2005 230 Nov 04/2005 231 Nov 04/2005 232 Nov 04/2005 233 Nov 04/2005 234 Nov 04/2005 235 Nov 04/2005 236 Nov 04/2005 237 Nov 04/2005 238 Nov 04/2005 239 Nov 04/2005 240 Nov 04/2005 241 Nov 04/2005 242 Nov 04/2005 243 Nov 04/2005 244 Nov 04/2005 245 Nov 04/2005 246 Nov 04/2005 247 Nov 04/2005 248 Nov 04/2005 249 Nov 04/2005 250 Nov 04/2005 250 A deleted 250 B deleted 251 Nov 04/2005 252 Nov 04/2005
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253 Nov 04/2005 254 Nov 04/2005 255 Nov 04/2005 256 blank Nov 04/2005 72-00-00 Servicing 301 May 02/2003 302 May 02/2003 303 May 02/2003 304 May 02/2003 305 May 02/2003 306 May 02/2003 307 May 02/2003 308 May 02/2003 309 May 02/2003 310 May 02/2003 311 May 02/2003 312 May 02/2003 313 May 02/2003 314 May 02/2003 315 May 02/2003 316 May 02/2003 317 May 02/2003 318 May 02/2003 319 May 02/2003 320 May 02/2003 321 May 02/2003 322 May 02/2003 323 May 02/2003 324 Mar 11/2005 325 May 02/2003 326 May 02/2003 327 May 02/2003 328 May 02/2003 329 May 02/2003 330 May 02/2003 331 May 02/2003 332 May 02/2003 333 May 02/2003 334 May 02/2003 335 May 02/2003 336 May 02/2003 CHAPTER
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337 May 02/2003 338 May 02/2003 339 May 02/2003 340 May 02/2003 341 May 02/2003 342 blank May 02/2003 72-00-00 Removal/ Installation 401 Mar 11/2005 402 Mar 11/2005 403 Mar 11/2005 404 Mar 11/2005 405 Mar 11/2005 406 Mar 11/2005 407 Mar 11/2005 408 Mar 11/2005 409 Mar 11/2005 410 blank Mar 11/2005 72-00-00 Adjustment/ Test 501 Mar 09/2001 502 Mar 01/2002 503 Jul 13/2001 504 Mar 09/2001 505 Jul 13/2001 506 Jul 13/2001 507 Mar 01/2002 508 Mar 01/2002 509 Mar 01/2002 510 Jul 13/2001 511 Mar 01/2002 512 Mar 01/2002 512 A Jul 13/2001 512 B blank Jul 13/2001 513 Mar 01/2002 514 Jan 16/2004 515 Mar 09/2001 516 blank Mar 09/2001 517 Mar 09/2001 518 blank Mar 09/2001 519 Mar 09/2001 520 blank Mar 09/2001 521 Mar 09/2001
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522 blank Mar 09/2001 523 Mar 09/2001 524 blank Mar 09/2001 525 Jan 16/2004 526 Mar 09/2001 72-00-00 Inspection Check 601 Jan 24/2006 602 Jan 24/2006 603 Jan 24/2006 604 Jan 24/2006 605 Jan 24/2006 606 Jan 24/2006 607 Jan 24/2006 608 Jan 24/2006 609 Jan 24/2006 610 Jan 24/2006 611 Jan 24/2006 612 Jan 24/2006 613 Jan 24/2006 614 Jan 24/2006 615 Jan 24/2006 616 Jan 24/2006 617 Jan 24/2006 618 Jan 24/2006 619 Jan 24/2006 620 Jan 24/2006 621 Jan 24/2006 622 Jan 24/2006 623 Jan 24/2006 624 Jan 24/2006 625 Jan 24/2006 626 Jan 24/2006 627 Jan 24/2006 628 Jan 24/2006 629 Jan 24/2006 630 Jan 24/2006 631 Jan 24/2006 632 Jan 24/2006 632 A Jan 24/2006 632 B Jan 24/2006 632 C Jan 24/2006 CHAPTER
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632 D Jan 24/2006 632 E Jan 24/2006 632 F Jan 24/2006 632 G Jan 24/2006 632 H Jan 24/2006 632 I Jan 24/2006 632 J Jan 24/2006 632 K Jan 24/2006 632 L Jan 24/2006 632 M Jan 24/2006 632 N Jan 24/2006 632 O Jan 24/2006 632 P Jan 24/2006 632 Q Jan 24/2006 632 R Jan 24/2006 633 Jan 24/2006 634 Jan 24/2006 635 Jan 24/2006 636 Jan 24/2006 637 Jan 24/2006 638 Jan 24/2006 639 Jan 24/2006 640 Jan 24/2006 640 A deleted 640 B deleted 640 C deleted 640 D deleted 640 E deleted 640 F deleted 640 G deleted 640 H deleted 640 I deleted 640 J deleted 641 Jan 24/2006 642 Jan 24/2006 643 Jan 24/2006 644 Jan 24/2006 645 Jan 24/2006 646 Jan 24/2006 647 Jan 24/2006 648 Jan 24/2006
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648 A deleted 648 B deleted 648 C deleted 648 D deleted 648 E deleted 648 F deleted 648 G deleted 648 H deleted 648 I deleted 648 J deleted 648 K deleted 648 L deleted 648 M deleted 648 N deleted 648 O deleted 648 P deleted 648 Q deleted 648 R deleted 648 S deleted 648 T deleted 649 Jan 24/2006 650 Jan 24/2006 651 Jan 24/2006 652 Jan 24/2006 653 Jan 24/2006 654 Jan 24/2006 655 Jan 24/2006 656 Jan 24/2006 657 Jan 24/2006 658 Jan 24/2006 659 Jan 24/2006 660 Jan 24/2006 661 Jan 24/2006 662 Jan 24/2006 663 Jan 24/2006 664 Jan 24/2006 665 Jan 24/2006 666 Jan 24/2006 667 Jan 24/2006 668 Jan 24/2006 669 Jan 24/2006 CHAPTER
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670 Jan 24/2006 671 Jan 24/2006 672 Jan 24/2006 673 Jan 24/2006 674 Jan 24/2006 675 Jan 24/2006 676 Jan 24/2006 677 Jan 24/2006 678 Jan 24/2006 679 Jan 24/2006 680 Jan 24/2006 681 Jan 24/2006 682 Jan 24/2006 683 Jan 24/2006 684 Jan 24/2006 685 Jan 24/2006 686 Jan 24/2006 687 Jan 24/2006 688 Jan 24/2006 689 Jan 24/2006 690 Jan 24/2006 691 Jan 24/2006 692 Jan 24/2006 72-00-00 Cleaning/ Painting 701 Jan 24/2006 702 Jan 24/2006 703 Jan 24/2006 704 Jan 24/2006 705 Jan 24/2006 706 Jan 24/2006 707 Jan 24/2006 708 Jan 24/2006 709 Jan 24/2006 710 Jan 24/2006 711 Jan 24/2006 712 Jan 24/2006 713 Jan 24/2006 714 Jan 24/2006 715 Jan 24/2006 716 Jan 24/2006 717 Jan 24/2006
CHAPTER
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718 Jan 24/2006 719 Jan 24/2006 720 Jan 24/2006 721 Jan 24/2006 722 Jan 24/2006 723 Jan 24/2006 724 Jan 24/2006 725 Jan 24/2006 726 Jan 24/2006 72-00-00 Approved Repairs 801 Mar 01/2002 802 Mar 01/2002 803 Mar 01/2002 804 Mar 01/2002 805 Mar 01/2002 806 Mar 01/2002 807 Mar 01/2002 808 Mar 01/2002 809 Mar 01/2002 810 Jan 16/2004 811 Jan 16/2004 812 blank Mar 01/2002 72-00-01 Fault Isolation 101 Nov 04/2005 102 Nov 04/2005 103 Nov 04/2005 104 Nov 04/2005 105 Nov 04/2005 106 Nov 04/2005 107 Nov 04/2005 108 Nov 04/2005 109 Nov 04/2005 110 Nov 04/2005 111 Nov 04/2005 112 Nov 04/2005 113 Nov 04/2005 114 Nov 04/2005 115 Nov 04/2005 116 Nov 04/2005 117 Nov 04/2005 118 Nov 04/2005 CHAPTER
SECTION PAGE DATE
119 Nov 04/2005 120 Nov 04/2005 121 Nov 04/2005 122 Nov 04/2005 123 Nov 04/2005 124 Nov 04/2005 125 Nov 04/2005 126 Nov 04/2005 127 Nov 04/2005 128 Nov 04/2005 129 Nov 04/2005 130 Nov 04/2005 131 Nov 04/2005 132 Nov 04/2005 133 Nov 04/2005 134 Nov 04/2005 135 Nov 04/2005 136 Nov 04/2005 137 Nov 04/2005 138 Nov 04/2005 139 Nov 04/2005 140 Nov 04/2005 141 Nov 04/2005 142 Nov 04/2005 143 Nov 04/2005 144 Nov 04/2005 145 Nov 04/2005 146 Nov 04/2005 147 Nov 04/2005 148 Nov 04/2005 149 Nov 04/2005 150 Nov 04/2005 151 Nov 04/2005 152 Nov 04/2005 153 Nov 04/2005 154 Nov 04/2005 155 Nov 04/2005 156 Nov 04/2005 157 Nov 04/2005 158 Nov 04/2005 159 Nov 04/2005
CHAPTER
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160 Nov 04/2005 161 Nov 04/2005 162 Nov 04/2005 163 Nov 04/2005 164 Nov 04/2005 165 Nov 04/2005 166 Nov 04/2005 167 Nov 04/2005 168 Nov 04/2005 169 Nov 04/2005 170 Nov 04/2005 171 Nov 04/2005 172 Nov 04/2005 72-00-02 Fault Isolation 101 Oct 20/2000 102 Sep 03/99 103 Oct 20/2000 104 Oct 20/2000 105 Sep 03/99 106 Sep 03/99 107 Sep 03/99 108 blank Sep 03/99 109 Sep 03/99 110 blank Sep 03/99 111 Sep 03/99 112 Sep 03/99 113 Sep 03/99 114 Sep 03/99 115 Sep 03/99 116 Sep 03/99 117 Sep 03/99 118 Sep 03/99 119 Sep 03/99 120 Sep 03/99 121 Sep 03/99 122 Sep 03/99 123 Sep 03/99 124 Sep 03/99 125 Sep 03/99 126 Sep 03/99 127 Sep 03/99 CHAPTER
SECTION PAGE DATE
128 Sep 03/99 129 Sep 03/99 130 Sep 03/99 131 Sep 03/99 132 Sep 03/99 133 Sep 03/99 134 Sep 03/99 135 Sep 03/99 136 Sep 03/99 137 Sep 03/99 138 Sep 03/99 139 Sep 03/99 140 Sep 03/99 141 Sep 03/99 142 Sep 03/99 143 Sep 03/99 144 Sep 03/99 145 Sep 03/99 146 Sep 03/99 147 Sep 03/99 148 Sep 03/99 149 Sep 03/99 150 Sep 03/99 151 Sep 03/99 152 Sep 03/99 153 Sep 03/99 154 Sep 03/99 155 Sep 03/99 156 Sep 03/99 157 Sep 03/99 158 Sep 03/99 159 Sep 03/99 160 Sep 03/99 161 Sep 03/99 162 Sep 03/99 163 Sep 03/99 164 Sep 03/99 165 Sep 03/99 166 Sep 03/99 167 Sep 03/99 168 Sep 03/99
CHAPTER
SECTION PAGE DATE
169 Sep 03/99 170 Sep 03/99 171 Sep 03/99 172 Sep 03/99 173 Sep 03/99 174 Sep 03/99 175 Sep 03/99 176 Sep 03/99 177 Sep 03/99 178 Sep 03/99 179 Sep 03/99 180 Sep 03/99 181 Sep 03/99 182 Sep 03/99 183 Sep 03/99 184 Sep 03/99 185 Sep 03/99 186 Sep 03/99 187 Sep 03/99 188 Sep 03/99 189 Sep 03/99 190 Sep 03/99
ENGINE - DESCRIPTION AND OPERATION 72-00-00 1. General 1 2. Description 1 A. Reduction Gearbox 1 B. Turbomachinery 9 C. Accessory Drives 11
D. Identification of Engine Bearings, Flanges and Stations 13
E. Oil System 19
F. Fuel and Control System 26
G. Propeller Control System 46
H. Inlet Temperature and Torque Sensing Systems 48
I. Ignition System 48
J. Performance Indicating System 51
K. Air System 53
3. Operation (A summary of the functions previously described) 64
4. Engine - Approved Fuels 64
A. Use of Approved Fuels 64
B. High Temperature Stability 71
C. Quality 71
D. Additives 71
E. Acceptable Fuels (Unrestricted Use) 75
F. Acceptable Fuels (Restricted Use) 77
G. Alternate/Emergency Fuels 78
5. Engine - Approved Lubricating Oils 78
A. General 78
B. Approved Oils 79
TABLE OF CONTENTS
ENGINE - DESCRIPTION AND OPERATION (Cont’d) 72-00-00
C. Dupont Oil Blue Dye (PWC05-026) 80
D. Oil Drain Period 80
E. Oil Analysis 83
ENGINE - FAULT ISOLATION 72-00-00
1. General 101
2. Consumable Materials 101
3. Special Tools 101
4. Fixtures, Equipment and Supplier Tools 101
5. Fault Isolation Chart Locations 101
ENGINE - MAINTENANCE PRACTICES 72-00-00
1. General 201
2. Consumable Materials 201
3. Special Tools 202
4. Fixtures, Equipment and Supplier Tools 202
5. Standard Torques 202
6. Torque Wrenches 203
A. General 203
B. Standard Torque Wrenches and Extensions 203
C. Power Torque Wrenches 205
7. General Torque Recommendations 206
A. Oil Lubricated Parts 206
B. Self-locking Nuts and Helical Coil Inserts 206
C. Castellated Nuts 207
D. Standard and Stepped Studs 207
E. Tube Nuts 207
TABLE OF CONTENTS
ENGINE - MAINTENANCE PRACTICES (Cont’d) 72-00-00 8. Locking 207 A. General 207 B. Keywashers 207 C. Lockwire 210 D. Retaining Rings 212 9. Marking of Parts 212 A. General 212 B. Permanent Marking 217 C. Temporary Marking 217 10. Lubrication 219 A. General 219
11. Tube-to-Boss Elbows, Elbow Adapters, Elbow Assemblies, Tees
and Tee Assemblies 219
A. Removal 219
B. Installation 219
12. Straight Nipples or Adapters, Bulkhead Couplings and Tube
Connector Nipples 221
A. Installation 221
13. Wiring Harness Connectors 221
A. General 221 B. Installation Procedure 221 14. Inspection 225 A. General 225 B. Inspection Procedures 225 C. Inspection Terms 226 D. Inspection Gages 226 TABLE OF CONTENTS SUBJECT PAGE
ENGINE - MAINTENANCE PRACTICES (Cont’d) 72-00-00
E. Magnetic Particle Inspection 231
F. Fluorescent Penetrant Inspection 231
G. Inspection of Fuel, Oil and Air Filters 232
15. Cleaning 232
A. General 232
B. Precautions 232
16. Bearings 233
17. Debris Analysis and Material Specifications 233
A. General 233
B. Filter Patch Check Debris Inspection/Analysis 233
C. Chip and Flake Analysis 234
D. Material Specifications 235 E. Laboratories 250 ENGINE - SERVICING 72-00-00 1. General 301 2. Consumable Materials 301 3. Special Tools 301
4. Fixtures, Equipment and Supplier Tools 302
5. Removal/Installation 302
A. Preparation of Shipping Container for Service or Storage 302
B. Removal of Engine from Shipping Container 302
C. Installation of Engine in Shipping Container 303
D. Removal of Reduction Gearbox from Shipping Container 308 E. Installation of Reduction Gearbox in Shipping Container 313 F. Removal of Turbomachinery from Shipping Container 314
TABLE OF CONTENTS
ENGINE - SERVICING (Cont’d) 72-00-00
G. Installation of Turbomachinery in Shipping Container 319
6. Preservation/Depreservation 320
A. General Engine Storage/Preservation Procedure 320
B. Oil System Preservation 323
C. Fuel System 324
D. Accessories 325
E. Desiccant and Humidity Indicator Reactivation 326
F. Depreservation (Engine) 326 G. Depreservation (Accessories) 329 7. Shipping 329 A. General 329 B. Shipping Method 331 8. Oil Draining 332
A. Main Oil Tank and/or RGB 332
9. Chip Collector - Replacement 333
A. Procedure 333
10. Oil System Flushing and Filling 335
A. Procedure 335
11. Oil System Filling 337
A. Oil Filling Procedure 337
B. Replenishing Empty Oil System 338
12. Oil Level Check and Top-up 339
A. General Oil Level Check 339
B. Top-up 339
TABLE OF CONTENTS
ENGINE - SERVICING (Cont’d) 72-00-00
13. Oil Consumption Trend Monitoring 340
A. General 340 B. Procedure 340 ENGINE - REMOVAL/INSTALLATION 72-00-00 1. General 401 2. Consumable Materials 401 3. Special Tools 401
4. Fixtures, Equipment and Supplier Tools 402
5. Removal 402
A. Engine from Airframe 402
B. Engine from Stand (PWC34200) 402
6. Installation 403 A. Engine in Airframe 403 B. Engine in Stand (PWC34200) 409 ENGINE - ADJUSTMENT/TEST 72-00-00 1. General 501 2. Consumable Materials 501 3. Special Tools 501
4. Fixtures, Equipment and Supplier Tools 501
5. Engine Ground Running Operating Limits 501
6. Engine/Component Replacement Test Requirements 501
7. Overtorque and Overtemperature Limits 502
8. Starting 503
A. Prestart 503
B. Wet Motoring 503
TABLE OF CONTENTS
ENGINE - ADJUSTMENT/TEST (Cont’d) 72-00-00
C. Dry Motoring (to purge engine of fuel after wet motoring run or in the event of fire occurring in the engine after starting or
permit a compressor wash to be carried out.) 504
D. Start 504 9. Shutdown 507 A. Procedure 507 10. Checks 507 A. Oil Pressure 507 B. Leak Check 508
C. Ground IDLE - NH GOVERNING 508
D. Flight IDLE - NH GOVERNING 508
E. Flight IDLE/MIN NP GOVERNING 508
F. REVERSE/MIN. and MAX NP Governing 508
G. Maximum Forward Governing (T.O.P or ITT/T6 Limit) 509
H. EEC Manual Reversion 509
I. Autofeather and Uptrim (both engines running) 509
J. Power Assurance Check 512
K. Acceleration Check 514
ENGINE - INSPECTION/CHECK 72-00-00
1. General 601
2. Consumable Materials 601
3. Special Tools 601
4. Fixtures, Equipment and Supplier Tools 601
5. Periodic Inspection 602
6. Rotor Components - Service Life 602
7. Engines with Defects Outside Specified Limits 602
TABLE OF CONTENTS
ENGINE - INSPECTION/CHECK (Cont’d) 72-00-00
8. Low Pressure and High Pressure Impellers - Foreign Object
Damage 603 A. LP Impeller 603 B. HP Impeller 609 9. Borescope Inspection 616 A. General 616 B. Side-viewing Adapter 616 C. Light Source 617 D. Camera 617 E. Guide Tubes 619 F. Troubleshooting 619
G. Low Pressure Impeller 620
H. High Pressure Impeller 623
I. Fuel Pump and Oil Pump Drive Bevel Gears 623
J. Accessory Drive Bevel Gears (Towershaft) 625
K. Starter-generator Drive Gear 625
L. Intercompressor Case Air Plenum 627
M. No. 5 Bearing Cavity 629
N. Combustion Chamber Liner Assembly, HP Turbine Vane Ring
Segments and HP Turbine Blades 631
O. LP Turbine Blades and Stator Assembly 632C
P. Power Turbine Stator Assembly and First-stage Blades 632E
Q. No. 6 and 7 Bearing Vent Transfer Tube. 632H
R. Second-stage Power Turbine Blades and Vane Ring 632H
S. RGB First-stage Helical and Input Shaft Gears 632I
T. RGB Second-stage Gears (Bull Gear and Layshaft Pinions) 632M TABLE OF CONTENTS
ENGINE - INSPECTION/CHECK (Cont’d) 72-00-00
10. Hot Section Component Borescope Inspection Criteria 632R
A. General 632R
B. Combustion Chamber (Small Exit Duct, Inner and Outer Liner
Assemblies) 632R
C. High Pressure (HP) Turbine Vane Segments 643
D. HP Turbine Blades 646
E. HP Turbine Shroud Segment 654
F. LP Turbine Stator . 678
G. LP Turbine Blades 678
H. First- and Second-stage Power Turbine Vanes 681
I. First- and Second-stage Power Turbine (PT) Blades 685
11. Gear Teeth Inspection 685
A. Acceptable Conditions 685
B. Non-acceptable Conditions 688
12. Cracks in Turbine Support Case Inner Wall 688
13. Cracks in Gas Generator Case Firewall Support Ring 689
A. Visual Inspection 689
ENGINE - CLEANING/PAINTING 72-00-00
1. General 701
2. Consumable Materials 701
3. Special Tools 701
4. Fixtures, Equipment and Supplier Tools 701
5. Engine Cleaning 702
A. External Wash 702
B. Compressor Wash 702
TABLE OF CONTENTS
ENGINE - CLEANING/PAINTING (Cont’d) 72-00-00
C. Turbine Wash 719
ENGINE - APPROVED REPAIRS 72-00-00
1. General 801
2. Consumable Materials 801
3. Special Tools 801
4. Fixtures, Equipment and Supplier Tools 801
5. Helical Coil Insert Replacement 802
A. General 802
B. Procedure (same size insert replacement) 802
C. Procedure (oversize insert replacement) 802
6. ’Keensert’ Insert Replacement 803
A. Procedure 803
7. Stud Replacement 806
A. Procedure 806
8. Stud Hole Repair 808
A. Procedure 808
9. Anodic Film Repair of Aluminum 808
A. Procedure 808
10. Chromate Surface Repair of Magnesium 809
A. General 809
B. Procedure 810
11. Jacking Insert Replacement 811
A. Procedure 811
ENGINE - FAULT ISOLATION 72-00-01
1. General 101
TABLE OF CONTENTS
ENGINE - FAULT ISOLATION (Cont’d) 72-00-01
2. Consumable Materials 101
3. Special Tools 101
4. Fixtures, Equipment and Supplier Tools 101
5. Fault Isolation Fault Index 101
ENGINE - FAULT ISOLATION 72-00-02
1. General 101
2. Consumable Materials 101
3. Special Tools 101
4. Fixtures, Equipment and Supplier Tools 101
5. Electronic Fuel Control System 101
A. Procedures 101
6. Servicing Connectors with Aircraft Electrical Power On 103
A. Procedure 103
7. Fault Isolation Fault Index 104
8. Fault Isolation Steps 106
TABLE OF CONTENTS
ENGINE - DESCRIPTION AND OPERATION 1. General (Ref. Figs. 1 and 2)
The PW127H turboprop engine has two centrifugal impellers driven by independent axial turbines, a reverse flow annular combustor and a two-stage power turbine which provides the drive for the reduction gearbox. The engine has two modules: a reduction gearbox module and a turbomachinery module. The modules are joined to form a rigid unit. Provision is made for the installation of airframe equipment on the engines.
2. Description
A. Reduction Gearbox (Ref. Figs. 3, 4 and 5)
The reduction gearbox has an accessory drive cover and three housings: the front housing, the rear housing and the input housing (which together make up the housing set). Reduction is accomplished by a two-stage geartrain.
(1) Front Housing
The front housing holds the front roller bearings for the two second-stage gearshafts and the propeller shaft, and the ball thrust bearing for the propeller shaft. The propeller shaft seal is under a cover on the front housing.
In front of each gearshaft are mounting pads. A propeller brake is fitted to the left pad. These pads are provided with seal drains blanked off with flight closures. The propeller brake (Ref. Fig. 5) is a hydromechanical type actuated by solenoid valves which are energized by an airframe-mounted control unit which controls the braking and unbraking sequences. The brake is used to immobilize the propeller when the engine is running and providing electricity and compressor air for off-engine use. Push buttons on each solenoid valve allow manual operation of the brake release system during maintenance or when an electrical failure has occurred. A mounting pad is provided on the right side of the front housing to accommodate an electric feathering pump. The pad has oil ports that are connected to an internal oil tank which is part of the rear housing.
The data plate of the reduction gearbox module is attached to the left side of the front housing.
At the one and eleven o’clock positions on the front housing flange are two lifting brackets.
(2) Rear Housing
The rear housing carries the second-stage reduction gear and drive pinions,
propeller shaft rear roller bearing, second-stage reduction gear rear roller bearings, front roller bearing of the input shaft and the front roller bearings of both first-stage helical gears.
NP PULSE PICK−UP PROBE
ENGINE FRONT MOUNTING PAD
TORQUE MOUNTING PAD
AMBIENT PRESSURE TRANSDUCER TOTAL INLET PRESSURE TRANSDUCER OIL INLET (FROM REMOTE OIL COOLER) OIL PRESSURE REGULATING VALVE T6 BUS−BARS FUEL INLET OIL PRESSURE FILTER IMPENDING BYPASS INDICATOR OIL PRESSURE FILTER ENGINE ELECTRONIC CONTROL TORQUE SENSOR GEARBOX DATA PLATE
CHIP DETECTOR MOUNTING PAD
MECHANICAL FUEL CONTROL UNIT
FUEL PUMP OUTLET FILTER
LOW OIL PRESSURE SWITCH
MAIN OIL PRESSURE SENSOR
OIL LEVEL INDICATOR
C61309B Typical Engine
REAR ENGINE MOUNTING PAD ACCESSORY GEARBOX BREATHER TUBE ENGINE FRONT MOUNTING PAD TORQUE MOUNTING PAD TORQUE SENSOR IGNITION EXCITER AIR INLET IGNITION HARNESS REDUCTION GEARBOX SCAVENGE OIL FILTER OIL OUTLET
(TO REMOTE OIL COOLER) OIL PUMP
PACK NO. 6 & 7 BEARING
SCAVENGE PIPE FUEL PUMP INLET FILTER GEARBOX OIL PRESSURE PIPE ENGINE FRONT MOUNTING PAD ELECTRIC FEATHERING PUMP MOUNTING PAD OIL TO FUEL
T6 TRIM RESISTOR OIL SCAVENGE FILTER
IMPENDING BYPASS INDICATOR IGNITER PLUG
HIGH PRESSURE ROTOR (NH) PULSE PICK−UP PROBE STARTER MOUNTING PAD
TOTAL INLET TEMPERATURE SENSOR
PRESSURIZING AIR SUPPLY PIPE
ENGINE DATA PLATE HEATER
C61311A Typical Engine
P0/T0 PRESSURE/TEMPERATURE STATIONS P1/T1 P1.5/T1.5 P1.8/T1.8 P2/T2 FLANGES A B BEARINGS 1 2 D C C11121D_1 Bearings, Flanges and Stations
P2.5/T2.5 P3/T3 P4/T4 P5/T5 P6/T6 P7/T7 P8/T8 E 3 4 F 5 K 6 7 C11121D_2 Bearings, Flanges and Stations
ENGINE MOUNTING PAD DATA PLATE TORQUE MOUNT CHIP DETECTOR AND STRAINER GEARSHAFT COVERS PROPELLER SHAFT SEAL DRAIN REAR HOUSING LIFTING BRACKETS FRONT HOUSING PROPELLER SHAFT PROPELLER SHAFT FLANGE FEATHERING PUMP MOUNT PAD TORQUE MOUNT ENGINE MOUNTING PAD INPUT DRIVE HOUSING ACCESSORY DRIVE COVER TOP MOUNTING PAD C38713 Reduction Gearbox - 3
⁄
4ViewREDUCTION GEARBOX REAR HOUSING
OVERSPEED GOVERNOR DRIVE GEARSHAFT
135 TOOTH SECOND STAGE SPUR GEAR
PROPELLER SHAFT
38 TOOTH SECOND STAGE SPUR GEAR
REDUCTION GEARBOX FRONT HOUSING FIRST STAGE HELICAL GEAR HELICAL INPUT GEARSHAFT INTERGRATED DRIVE GENERATOR PROPELLER SHAFT FRONT ROLLER BEARING IDLER DRIVE SPUR GEARSHAFT PROPELLER SHAFT SEAL PROPELLER MOUNTING FLANGE FIRST STAGE HELICAL GEAR 38 TOOTH SECOND STAGE SPUR GEAR
PROPELLER BRAKE COUPLING GEARSHAFT C69157 Reduction Geartrain Figure 4
PROPELLER BRAKE
SOLENOID VALVES
MANUAL CONTROL
C38712 Propeller Brake and Propeller Brake Control - 3/4 View
The front engine three main mounting pads are located as follows: two on either side of the housing, and the third at the top center. Torque mounts are located at the 5 and 7 o’clock positions on the housing.
The accessory drive cover is mounted on the top rear face.
The propeller (NP) pulse pickup probe is installed in a mounting pad at the 11 o’clock position.
On the bottom right side is a pad for the chip detector and oil strainer. Another chip detector and strainer are installed on the upper left side.
The propeller valve module is mounted on a pad behind, and driven by, the propeller shaft.
(3) Input Drive Housing
The input drive housing carries the rear roller bearings of the input driveshaft and both layshafts.
Two torque sensors are mounted on pads located opposite one another on the horizontal centerline of the input drive housing.
(4) Accessory Drives
The overspeed governor/pump assembly is mounted on the right pad and driven by the 135-tooth second-stage gear. An oil cooled integrated drive generator (IDG) is mounted on the left pad and is driven by the idler gear, which is also driven by the 135-tooth second-stage gear.
B. Turbomachinery
The turbomachinery consists of four sections, contained in six casings (Ref. Fig. 6). The casings are bolted together at flanges (Ref. Fig. 2).
(1) Air Inlet Section
The air inlet section consists of the front inlet case and the rear inlet case bolted together at flange C.
The front inlet case has the engine electronic control (EEC) and autofeather unit (AFU) mounted on the left side, and the fuel-cooled oil cooler, ignition exciters and turbomachinery data plate on the right side. An access plate is on its top surface. The forward flange of the front inlet case has two integral lifting brackets and is connected to the RGB at flange B.
The rear inlet case joins the front case to the low pressure (LP) diffuser case at flange D. The case contains two bearings (No. 1 and 2) and seals for the power turbine shaft. Mounting pads are provided for accessories. The engine oil tank forms part of the casing.
OIL TANK INTERCOMPRESSOR CASE GAS GENERATOR CASE
FRONT INLET CASE TURBINE SUPPORT FUEL MANIFOLD & NOZZLES DIFFUSER EXIT
DUCTS L.P. DIFFUSER CASE
REAR INLET CASE INLET SECTION
TURBINE SECTION COMPRESSOR
COMBUSTION SECTION SECTION CASE C69158A Turbomachinery Figure 6
(2) Compressor Section
The compressor section comprises the low pressure (LP) and high pressure (HP) independent centrifugal impellers. These are contained within the LP diffuser case (flange D to E) and the intercompressor case (flange E to F) and the front of the gas generator case (flange F to K).
Diffuser pipes connect the diffuser case, which contains the LP impeller, to the intercompressor case. Two ball bearings (No. 3 and 4) are housed in the
intercompressor case. The No. 5 roller bearing is contained in the gas generator case.
A lifting bracket is located at the twelve o’clock position on flange K of the gas generator case.
A Y-adapter and non-return valve are located at the 12 o’clock position on the intercompressor case to supply low pressure air for use in the environment control system of the aircraft.
(3) Combustion Section
The annular reverse-flow combustion chamber is contained in the gas generator case. The fuel manifold is mounted around the exterior of the gas generator case, with spray nozzles which protrude into the combustion chamber liner. Two
igniter plug bosses are provided on the gas generator case, with corresponding bosses in the liner. The gas generator case incorporates an air bleed pad through which P3 air is supplied for off-engine use at low power and during starting. (4) Turbine Section
The LP and HP turbines are housed in the rear of the gas generator case, and the power turbines (PT) in the turbine support case. Concentric shafts connect the two-stage power turbine to the gearbox and the single-stage LP and HP turbines to the impellers. The central PT shaft is supported by the No. 1 (ball), No. 2 (roller) and No. 7 (roller) bearings. The intermediate LP turbine shaft is supported by the No. 3 (ball) and No. 6 (roller) bearings. The HP turbine shaft (integral with
impeller) is supported by the No. 4 (ball) and No. 5 (roller) bearings. C. Accessory Drives (Ref. Fig. 7)
An inclined bevel gearshaft (5) transmits drive from a gear (4), secured to the impeller (3) forward of No. 4 bearing, to the bevel gear (2) of the accessory drive coupling gearshaft (1). The centrifugal breather impeller (8) is mounted on the gearshaft (1). A spur gear (14) drives the fuel pump driveshaft (6) through gear (11), and another spur gear (7) meshes with gear (10) on the starter-generator driveshaft (9). Provision is made for hand cranking the HP rotor using a socket wrench extension tool in the end of the starter-generator driveshaft. Access is gained after removal of a cover opposite the starter-generator. The oil pumps are driven by driveshaft (13) through bevel gears (12) and (15).
3 4 5 12 6 11 16 2 1 14 7 10 9 8 13 15 C11186C Turbomachinery Accessory Drive Geartrain
D. Identification of Engine Bearings, Flanges and Stations (1) Engine Bearing Identification (Ref. Fig. 8)
All the bearings used in the engine have position numbers from 1 thru 30 as per steps (2), (3) and (4).
NOTE: The term ‘‘Not Used’’ is given to bearing numbers which are not, at this time, applicable to the engine model specified in this manual.
(2) Engine Main Bearings
The main bearings in the turbomachinery have numbers per Table 1. TABLE 1, Main Bearing Identification
BEARING NO. POSITION TYPE
1 Power Turbine Shaft Ball
2 Power Turbine Shaft Roller
3 Low-pressure Impeller Ball
4 High-pressure Impeller Ball
5 High-pressure Impeller Roller
6 Low-pressure Turbine Roller
7 Power Turbine Shaft Roller
Key to Figure 7
1. Accessory Drive Coupling Gearshaft 2. Bevel Gear
3. HP Impeller 4. Bevel Gear 5. Gearshaft
6. Fuel Pump Driveshaft 7. Spur Gear
8. Centrifugal Breather Impeller 9. Starter-generator Driveshaft 10. Spur Gear
11. Spur Gear 12. Bevel Gear
13. Oil Pump Driveshaft 14. Spur Gear
15. Bevel Gear 16. Bevel Gear (Ref.)
B
B
A
A
No. 18
BEARING BEARINGNo. 15
No. 19
BEARING BEARINGNo. 9 BEARINGNo. 8
C32417C_1 Bearing Identification
No. 25
BEARING BEARINGNo. 25 BEARINGNo. 28 BEARINGNo. 28 BEARINGNo. 29
No. 6 BEARING
No. 7 BEARING
No. 1
BEARING BEARINGNo. 2 BEARINGNo. 3 BEARINGNo. 30 BEARINGNo. 4 BEARINGNo. 5 (FRONT) (REAR) (FRONT) (REAR) (LOWER) No. 27
BEARING
C32417C_2 Bearing Identification
NO.8 BEARING NO.9 BEARING NO.11 BEARING NO.12 BEARING NO.13 BEARING NO.14 BEARING SECTION
A−A
FWD NO.11 BEARING NO.12 BEARING NO.13 BEARING NO.14 BEARING FWD SECTIONB−B
NO.20 BEARING (FRONT) NO.20 BEARING (REAR) NO.22 BEARING (FRONT) NO.22 BEARING (REAR) NO.23 BEARING (FRONT) NO.23 BEARING (REAR) C33359 Bearing Identification Figure 8 (Sheet 3)SECTION NO. 25 BEARING (FRONT) NO. 24 BEARING (FRONT) NO. 24 BEARING (REAR) NO. 25 BEARING (REAR) NO. 26 BEARING (FRONT) NO. 26 BEARING (REAR)
C−C
F W D C32419 Bearing Identification Figure 8 (Sheet 4)(3) Reduction Gearbox Bearings
The RGB bearings have numbers per Table 2.
TABLE 2, Reduction-gearbox Bearing Identification
BEARING NO. POSITION TYPE
8 Input Drive Shaft Roller
9 Input Drive Shaft Roller
10 NOT USED NOT USED
11 First-stage Helical Gear Roller
12 First-stage Helical Gear Roller
13 Second-stage Spur Gearshaft (Pinion Gear) Roller
14 Second-stage Spur Gearshaft (Pinion Gear) Roller
15 Propeller Shaft Roller
16 NOT USED NOT USED
17 NOT USED NOT USED
18 Propeller Shaft Ball
19 Propeller Shaft Roller
20 (Front and Rear) Overspeed-governor Drive Gearshaft Roller
21 NOT USED NOT USED
22 (Front and Rear) Idler Drive Gearshaft Roller
23 (Front and Rear) Integrated Drive Generator Gearshaft Roller (4) Accessory Gearbox Bearings
The accessory gearbox bearings, in the upper section of the rear inlet case, and in the angle drive gearbox which is on the intercompressor case, have numbers per Table 3.
TABLE 3, Accessory-gearbox Bearing Identification
BEARING NO. POSITION TYPE
24 (Front and Rear) Starter-generator drive Gearshaft Roller
25 (Front) Main-accessory-drive Gearshaft Roller
25 (Rear) Main-accessory-drive Gearshaft Ball
26 (Front) Fuel-pump Drive Shaft Roller
26 (Rear) Fuel-pump Drive Shaft Ball
27 Oil-pump Drive Shaft Ball
TABLE 3, Accessory-gearbox Bearing Identification (Cont’d)
BEARING NO. POSITION TYPE
28 (Rear) Accessory-drive Horizontal Gearshaft Ball
29 (Upper) NOT USED NOT USED
29 (Lower) Accessory Drive Housing Roller
30 Accessory-drive Lower Bevel Gearshaft Ball
E. Oil System (Ref. Figs. 9 through 13)
The oil system is a wet sump system, cooled by an aircraft mounted air-cooled oil cooler and an integral fuel-cooled oil cooler. The oil is stored in a tank that is integral with the rear inlet case. The tank has a filler neck and cap, contents gage and scavenge chip detector. The system is composed of three subsystems: the pressure system, which supplies oil to the reduction gearbox and turbomachinery, the scavenge system, which returns the used oil to the tank and the vent and breather system which vents the bearing cavities and removes oil from the vented air (Ref. Figs. 9 and 10).
(1) Pressure System (a) Turbomachinery
A spur gear type pressure pump is mounted, in a pack with the scavenge pump, on the right side of the rear inlet case. An integral cast passage connects the oil tank to the inlet side of the pump. A pressure relief valve returns oil to the tank to prevent a pressure surge during cold starting.
Airframe-supplied tubes connect the outlet to the airframe air cooled oil cooler. From the cooler the oil flows via a heat exchanger (airframe component) to the pressure regulating valve and the pressure filter.
The pressure regulating valve (Ref. Fig. 11) consists of a piston valve and spring in a ported sleeve. It maintains a constant oil pressure above and in relation to the air pressure in the No. 3 and 4 bearing cavity. If oil output pressure, taken from a tapping downstream of the check valve, overcomes the air
pressure plus spring pressure, the valve opens a port. Oil is bled from the main pressure line by the port and returned to the inlet side of the pump, reducing output pressure. Air pressure plus spring pressure overcomes the reduced oil pressure, closing the bleed port at the desired pump output pressure. The check valve output pressure is also connected, via a restrictor to an oil pressure transducer and to the low oil pressure switch.
The pressure filter has a bypass valve to ensure adequate flow if the filter is blocked; an indicator warns of impending blockage. From the filter the oil flows in two directions: to the oil pressure check valve housing and to the fuel heater (then, in turn, to the fuel-cooled oil cooler).
TO REDUCTION GEARBOX
OIL
COOLER OIL TO FUEL HEATER
OIL PRESSURE
TRANSDUCER AIR FROM NO.3 & 4 BEARING CAVITY MAIN OIL PRESSURE FILTER RESTRICTOR PRESSURE REGULATING VALVE IMPENDING BYPASS INDICATOR
FROM OIL COOLER TO OIL COOLER
PRESSURE REIEF VALVE OIL PUMP (PRESSURE) LOW OIL PRESSURE SWITCH
VIA IDG HEAT EXCHANGER
C69190_1A Turbomachinery Oil System - Schematic
CHECK VALVE
BLEED LINE
OIL TEMP. BULB
RESTRICTOR
STRAINER STRAINER STRAINER
STRAINER STRAINER INLET STRUT ANTI− ICING VENT VENT ACCESSORY GEARBOX GRAVITY DRAIN NO.1 & 2 BEARING CAVITY JET PUMP GRAVITY DRAIN NO.3 & 4 BEARING CAVITY NO.5 BEARING CAVITY
DRIVESHAFT FROM H.P. SHAFT
OIL TANK
SCREEN CHIP DETECTOR
NO.6 & 7 BEARING CAVITY
BLOWDOWN
SCAVENGE FROM REDUCTION GEARBOX
NO.6 & 7 CAVITY SCAVENGE PUMP
PRESSURE OIL SCAVENGE OIL VENT AIR
DRAIN AND UNPRESSURIZED OIL
C69190_2A Turbomachinery Oil System - Schematic
PROPELLER VALVE MODULE PUMP ELECTRIC FEATHERING PUMP RESTRICTOR OVERSPEED MODE GOVERNING MODE DRAIN VALVE MODULE R.G.B. AUXILLARY
MAIN OIL PRESSURE FROM TURBOMACHINERY DRAIN ACTUATOR CHIP DETECTOR SCREEN REDUCTION GEARBOX SCAVENGE PUMP SCAVENGE OIL SIGNAL PRESSURE OIL ENGINE OIL (PRESSURE) PROPELLER
PROPELLER
REDUCTION GEARBOX TURBOMACHINERY
PROPELLER VALVE MODULE OIL (BOOSTED)
REDUCTION GEARBOX SCAVENGE FILTER
BYPASS INDICATOR
MAIN OIL TANK OVERSPEED GOVERNOR BYPASS PRESSURE OIL DISTRIBUTION BY INTERNAL GALLERIES OIL TANK (PRESSURIZED) IMPENDING C38658 Reduction Gearbox Oil System - Schematic
OIL IN
OIL OUT
BEARING OIL PRESSURE SENSING
AIR PRESSURE SENSING FROM NO.3 & NO.4 BEARING CAVITY
PORT NOT USED
C31422 Oil Pressure Regulating Valve - 3
⁄
4CutawayOil goes through internal passages to the check valve housing. After entering the housing, the oil flows in two directions. One part goes through an internal passage in the housing wall, past the temperature bulb and externally to a connection on the rear inlet case. The other part goes through the check valve after 25% NH has been exceeded.
From the connection on the rear inlet case, oil flows by internal passages to the accessory gearbox through the inlet struts (for de-icing) to the No. 1 and 2 bearing cavity. Some of the accessory gearbox oil flows via a strainer to lubricate the drive gears and associated components. Oil flowing to the No. 1 and 2 bearing cavity passes through a strainer. Pressure oil is also used to actuate a jet pump which scavenges No. 2 bearing area.
The check valve consists of a piston valve and spring in a ported sleeve. During starting and shutdown, the valve stops oil going to the No. 3, 4, 5, 6 and 7 bearing cavities when pump outlet pressure is below a minimum value. This ensures that sufficient pressurized air is available at the bearings to enable the seals and blowdown scavenge system to function correctly and prevent oil flooding. From the check valve, oil flows through strainers to lubricate the bearings and associated components in the bearing cavities. Oil flows through a restrictor before reaching the strainer in the line to the No. 6 and 7 bearing cavity.
Oil flows through tubes to the oil-to-fuel heater and fuel-cooled oil cooler, then to the reduction gearbox and oil-cooled AC generator.
The fuel-cooled oil cooler (Ref. Fig. 12) is a heat exchanger with two flow circuits: engine lubricating oil and fuel. The oil circuit has two flow paths (bypass and internal) and a valve that controls flow between the paths. The valve remains in the open position, allowing oil to bypass the core until the temperature reaches 60 to 71°C (140-160°F). Within this temperature range bypass flow is cut off and routed through the internal path. To ensure the cooler is not over pressurized, the valve opens, allowing oil to bypass when the pressure
differential across the valve exceeds 40 psig (276 kPa). (b) Reduction Gearbox
Inside the gearbox (Ref. Fig. 10) the oil flows into an auxiliary oil tank (which is part of the casting). The auxiliary tank is pressurized when the engine is running, and is always full of oil (even when the engine is not running).
Oil from the tank flows, by internal passages and tubes, to the electric feathering pump and the propeller valve module (PVM) pump. The PVM receives
pressure oil from the electric feathering pump and the PVM pump and signal pressure oil from the overspeed governor (when in the governing mode). In the overspeed mode, signal pressure oil is drained through the overspeed
governor. Pressure oil from the PVM actuates the pitch control mechanism in the propeller.
Oil from the auxiliary tank is distributed through internal galleries to the reduction and accessory geartrains and bearings.
OIL OUT FUEL OUT FUEL IN OIL IN TEMPERATURE CONTROL VALVE OIL OUT FUEL OUT OIL IN OIL IN FUEL IN DETAIL
A
A
OIL OUT C63098 Fuel-cooled Oil Cooler - Schematic(2) Scavenge System (a) Reduction Gearbox
Scavenge oil from the gearbox accessories, gears and bearings drains into a cavity in the bottom of the reduction gearbox rear housing. The cavity has a chip detector. A scavenge pump, which is part of the pump pack on the right side of the rear inlet case, draws the oil through an external tube on the left side of the front inlet case. The tube is looped upward to prevent gearbox oil from
flooding the oil tank when the engine is not running. The tube connects to an internal oilway (which provides anti-icing of the intake) in the front inlet case. From the inlet case, the oil flows through a tube to the scavenge pump, then through the scavenge filter, which is equipped with a valve to bypass the filter in the event of blockage. An indicator warns of impending blockage. From the scavenge filter, the oil flows to the tank.
(b) Turbomachinery
Oil from the accessory casing and the No. 1 bearing cavity is scavenged by gravity. The No. 2 bearing cavity oil is scavenged through a venturi by gravity aided by pressure oil, which induces a jet-pump action. Oil from the No. 3, 4 and 5 bearing cavities is scavenged by gravity and assisted by air (blow-down) from the bearing labyrinth seals. The No. 6 and 7 bearing cavity oil is
scavenged through an external tube connected to the scavenge pump. (3) Vent and Breather System
The oil tank and No. 1 and 2 bearing cavity are vented internally, and the No. 6 and 7 bearing cavity externally, to the accessory gearbox. A centrifugal oil separator (breather impeller) installed in the accessory gearbox removes oil before vented air is carried by an external tube and discharged into the exhaust.
The impending bypass indicators (Ref. Fig. 13) fitted to the pressure and scavenge filters sense pressure filter differential. When activated, a signal gives advance warning of a filter blockage.
F. Fuel and Control System (Ref. Figs. 14 through 21)
The engine fuel and control system governs the power produced by the engine by controlling the fuel flow. The fuel flow is controlled by the power lever and fuel shut off (condition) lever through two integrated systems: the mechanical fuel system and the electronic fuel system.
(1) Engine Fuel System
The engine mechanical fuel system (Ref. Fig. 14) is made up of a fuel heater, a fuel pump and a mechanical fuel control unit (MFCU), which are mounted on the accessory drive casing. It also comprises a flow divider and dump valve and fuel nozzle manifold mounted on the gas generator case.
RIGHT SIDE − SCAVENGE OIL FILTER
LEFT SIDE − MAIN PRESSURE OIL FILTER
C30204A Oil System Impending Bypass Indicators - Location
(a) The fuel heater (Ref. Fig. 15) consists of a filter and fin-type heater in two integral housings. The filter housing contains a bypass valve to ensure an adequate fuel flow in the event of blockage and an indicator to warn of impending blockage. The heater housing is divided into two circuits. Turbomachinery lubricating oil flows through one circuit to transfer heat to the fuel, which flows through the other circuit. A thermal sensor in the fuel circuit operates a
valve to regulate the oil flow in order to maintain the required fuel temperature. The fuel pressure differential switch located in the fuel filter housing outlet port activates a warning indicator.
(b) The fuel pump (Ref. Fig. 16) is a positive displacement spur gear assembly consisting of a fuel ejector (jet pump), a self-relieving inlet screen, two spur gears, an outlet filter and a bypass valve. Fuel from the MFCU bypass outlet passes through the jet pump, positioned ahead of the main inlet, to maintain a constant inlet pressure. The self-relieving inlet screen, when blocked, lifts from its seat and allows fuel to enter the pump housing. Two spur gears pump fuel through the outlet filter. A bypass valve diverts fuel to the outlet port in the event of filter blockage: the differential pressure switch signals the impending blockage and activates a warning.
(c) The mechanical fuel control unit (MFCU) (Ref. Figs. 17 and 18), mounted on the fuel pump, controls the engine fuel flow and thus the power output. The MFCU consists of the following components:
1 Power Lever and Cam Assembly:
The power lever shaft incorporates two speed set cams, which move a cam lever when the power lever is advanced. A spring connects the cam lever to the governor lever and exerts a force on the governor lever as a function of PLA. The governor lever is pivoted, and one end operates against an airflow restrictor to form the governor orifice (Ag). A ball bearing on the governor lever contacts the top of the flyweight bearing assembly. When the power lever is advanced, the cam applies tension to the spring, which applies a force on the governor lever to close Ag.
2 Flyweight Assembly:
The flyweights are mounted on a platform on the driveshaft, and as the driveshaft revolves, centrifugal force causes the weights to pivot about their mounting points and contact the bottom face of the bearing assembly. As the driveshaft speed increases, increased centrifugal force causes the weights to apply an increasing force against the bearing assembly. This causes the bearing assembly to move upward on the driveshaft and apply pressure to the ball bearing on the governor lever arm. The governor orifice Ag opens whenever the driveshaft speed increases enough to overcome the force applied by the governor lever spring.
3 Orifices (Fixed and Variable):
High pressure compressor discharge pressure (P3) is supplied to the MFCU and metered through a fixed orifice to produce Px pressure. Px is used to pressurize the chamber containing the acceleration bellows, inside
the deceleration bellows and the governing bellows, and is metered
through a fixed orifice to produce Py pressure. Py pressurizes the chamber containing the deceleration and governing bellows and is tapped off
(then vented to atmosphere) via the governor (Ag) and stepper motor (Ap) flapper valve orifices. In addition, a Py tapping is connected to the
overspeed governor.
4 Flapper Valves (Ag and Ap):
Ag is controlled by the mechanical speed governor and Ap, which parallels Ag, by the stepper motor. Movement of either flapper valve changes Py with respect to Px and repositions the bellows assembly.
5 Mode Cam Select Mechanism:
The mode select mechanism is used to transfer control between the EEC and the MFCU. The system is activated automatically by the EEC when a system fault occurs and also by cockpit command. A solenoid operated pneumatic servo mechanism is used to select the appropriate cam which transfers control between the EEC and MFCU.
In EEC mode, a high mechanical governor speed schedule is selected by the EEC cam to close valve Ag and allow the EEC to control parallel valve Ap through the stepper motor. In manual mode, the manual cam holds valve Ap in the closed position and selects a low mechanical governor speed schedule which allows valve Ag to be controlled by the power lever
angle (PLA). 6 Bellows Assembly:
Consists of deceleration, governor and acceleration bellows connected by a shaft linked to the fuel metering valve. Pressure differential between
inside (Px) and outside (Py) pressures causes the deceleration bellows to expand and reduce fuel flow. An increase in Px pressure acting on the evacuated acceleration bellows increases fuel flow.
During acceleration, flapper valves Ag and Ap are closed; this equalizes and increases Px and Py air pressures. As Px increases, the acceleration bellows contract, opening the metering valve and increasing fuel flow. When governing, Py is reduced slightly below Px air pressure to give the fuel flow required to run at the selected power.
During deceleration, when the EEC is not operating, spring force on the governor flyweights is reduced, opening flapper valve Ag which bleeds and reduces Py pressure around the deceleration bellows (Px pressure in the bellows is not affected). The bellows expand, reducing fuel flow until the deceleration stop is contacted. As governor speed reaches the desired lower setting, spring force overcomes flyweight force, the valve closes and Py pressure increases. This moves the bellows away from the stop into the governing range to control fuel flow at the selected power level.
HEATED OIL INLET OUTLET FUEL FILTER BYPASS IMPENDING BYPASS SWITCH FUEL HEATER FUEL PRESSURE SENSING PORT
FUEL FILTER / HEATER UNIT
AIRFRAME / ENGINE FUEL CONNECTION
C17520_1A Fuel System - Schematic
FUEL PUMP UNIT
FUEL TEMP PORT
MOTIVE FLOW PUMP
BYPASS FLOW
DUMP VALVE PUMP
AIRFRAME EJECTOR PUMP
MOTIVE FLOW VALVE FLOW METER (OPTIONAL) OUTLET FILTER MECHANICAL FUEL CONTROL UNIT
BYPASS SELF RELIEVING SCREEN FLOW DIVIDER OIL COOLER INLET OUTLET
PRIMARY & SECONDARY FUEL NOZZLES OIL VENT AIRCRAFT DRAIN TANK WASTE FUEL EJECTOR TANK AIRFRAME / ENGINE CONNECTION C17520_2A Fuel System - Schematic
HEAT EXCHANGER AND VALVE BODY
FUEL IN OIL OUT OIL IN FUEL FILTER FUEL OUT PRESSURE DIFFERENTIAL SWITCH FUEL OUT FUEL FILTER FUEL IN OIL OUT OIL IN THERMAL ELEMENT VALVE COMPRESSION SPRING VALVE SLEEVE C15046B Fuel Heater -3
⁄
4View and SchematicOUTLET FILTER IMPENDING BYPASS SWITCH
FUEL IN
FUEL OUT
BYPASS FUEL RETURN OUTLET FILTER
BYPASS VALVE
SELF RELIEVING INLET SCREEN
OUTLET FILTER BYPASS VALVE
IMPENDING BYPASS SWITCH OUTLET FILTER GEAR PUMP INLET PORT OUTLET PORT FUEL EJECTOR BYPASS RETURN PORT
SELF RELIEVING INLET SCREEN
C15047B Fuel Pump - 3
⁄
4View and SchematicFUEL CONTROL RIGGING HOLE
FUEL SHUTOFF RIGGING HOLE POWER LEVER
FUEL SHUTOFF LEVER FUEL OUTLET FUEL MOTIVE FLOW OUTLET y 3 P AIR OUTLET P AIR INLET C30201 Mechanical Fuel Control Unit (MFCU) -3
⁄
4ViewMETERED FUEL OUT PRESSURIZING VALVE ON OFF CONDITION / FUEL SHUTOFF LEVER METERING VALVE P3 P0 MANIFOLD−PRESS. REGULATOR FUEL DRAIN BELLOWS ASSY. POWER LEVER IDLE
MAX. FORWARD MAX. REVERSE
DEC. BELLOWS GOV. BELLOWS ACC.BELLOWS PLA. INPUT RVDT BYPASS VALVE BYPASS RETURN TO PUMP TORQUE TUBE PRESSURE RELIEF VALVE MOTIVE FLOW VALVE BLEED P3 MOTIVE FLOW REGULATOR P3 AIR INLET FUEL INLET DRAIN EEC MODE CAM
& FOLLOWER LEVER MANUAL MODE CAM & FOLLOWER LEVER
DRAIN PRESSURE RELIEF VALVE NH DRIVE INPUT NH GOVERNOR FLYWEIGHTS GOVERNOR LEVER GOVERNOR ORIFICE (Ag) STEPPER MOTOR ORIFICE (Ap) ELECTRICAL CONNECTOR SERVO VALVE STEPPER MOTOR & GEARHEAD Py TO PROPELLER OVERSPEED GOVERNOR
MODE CAM SELECT SOLENOID
LEGEND DIFFERENTIAL PRESSURE
COMPRESSOR DISCHARGE PRESSURE HIGH PRESSURE ROTOR SPEED ENRICHMENT PRESSURE GOVERNING PRESSURE
ROTARY VARIABLE DIFFERENTIAL TRANSFORMER AMBIENT PRESSURE P3 NH Px Py RVDT P0 Px ORIFICE Py ORIFICE C15041A Mechanical Fuel Control Unit (MFCU) - Schematic
During deceleration, when the EEC is operating, the stepper motor opens flapper valve Ap, bleeding and reducing Py pressure around the deceleration bellows. The bellows expand, reducing fuel flow until the deceleration stop is contacted. When the desired power level is reached, the valve closes, increasing Py pressure to move the bellows away from the stop into the governing range.
7 Motive Flow Valve: The valve is spring loaded, closes and opens when the pressure of unmetered fuel overcomes the spring force. The valve provides fuel to operate a jet pump located in aircraft fuel tank.
8 High Pressure Relief Valve: Consists of a relief valve, a ported sleeve and a valve spring. The relief valve operates in parallel with the differential pressure regulator to prevent excessive buildup of fuel pressure in the main fuel control body.
9 Differential Pressure Regulator (Pd Regulator): Maintains a constant
pressure drop across the metering valve by bypassing excess fuel flow to the fuel pump ejector pump. Bimetallic disks under the spring compensate for variations in specific gravity due to fuel temperature change. An external adjustment screw on the regulator cover is used to adjust for maximum Pd.
10 Metering Valve: Composed of a needle valve operating in a sleeve.
Actuation of the valve changes the orifice area, which regulates the flow of fuel to the engine. Positioning of the needle valve is controlled by the bellows assembly in the pneumatic section through a torque tube that acts as a fuel/air seal.
11 Pressurizing Valve: Maintains a minimum fuel pressure in the MFCU during low flow conditions when starting.
12 Shutoff Valve: An input shaft driven by the condition/fuel shutoff lever
operates a valve that passes metered flow to the bypass port, consequently closing the pressurizing valve and shutting down the engine.
13 Manifold Pressure Regulator: Regulates starting fuel flow as a function of compressor discharge pressure (P3). The valve is normally open, and as P3 increases, the valve closes.
14 Stepper Motor: Alters the position of the valve (Ap) which bleeds Py
pressure to change metered fuel flow to the engine. The motor is controlled by the EEC.
15 Rotary Variable Differential Transformer: Fitted to the power lever shaft and signals power lever angle to the EEC.
17 The MFCU has an identification circuit in the wiring which is read by the EEC. If an MFCU having a lower fuel flow but not the identification circuit is installed on a PW127H engine, a fault is generated which prevents the MFCU from going into EEC mode. The code for the fault is stored in the EEC memory, thereby facilitating the identification of MFCUs which cannot meet the fuel flow requirements of PW127H engines.
(d) The flow divider and dump valve (Ref. Fig. 19) is connected to the fuel manifold at the bottom of the gas generator case (flange F to K). It comprises primary and secondary spool valves in a housing equipped with inlet and dump ports. The primary valve opens, giving access to the primary manifold, when the inlet fuel pressure overcomes the valve spring. The secondary valve opens when the primary manifold pressure overcomes the secondary valve spring. When the fuel inlet pressure ceases, the valves close the inlet and open the dump ports, allowing residual fuel to drain from the manifold through the flow divider to the dump port.
(e) The fuel manifold delivers fuel to the combustion chamber. The manifold consists of sheathed nozzle adapter assemblies (Ref. Fig. 20), which protrude into the combustion chamber, connected to three flexible tubes. One tube supplies primary fuel and the other two (which are connected), secondary fuel to the fuel nozzle adapters. Nozzle adapter assemblies are produced by Delavan. Some nozzles have a fine center hole for primary fuel flow and an annular orifice for secondary flow; others have no center hole and are equipped for secondary flow only. The sheath which surrounds the nozzle conveys air, from the compressor, to cool the nozzle and atomize the fuel.
(f) To ensure adequate drainage of fuel after shutdown, spring-loaded valves are installed at the front and rear of the underside of the gas generator case. The valves open when the pressure inside the case falls to near ambient
pressure. The front valve has an adapter installed with a tube connected to the adapter to drain the fuel to the main fuel drain valve. In addition, an elbow and tube is fitted to the exhaust duct and connects to the main fuel drain valve. (g) To eliminate atmospheric pollution and fuel wastage, the dump valve is
connected to a waste fuel ejector.
1 The fuel waste ejector (Ref. Fig. 21), located in the airframe, comprises a tank with inlet and outlet connections and a vent. The tank contains non-return valves, a motive flow ejector pump, a strainer, and a float-operated drain valve.
INLET PORT CLOSED PRIMARY, SECONDARY AND DUMP PORTS OPEN
INLET AND PRIMARY PORTS OPEN SECONDARY AND DUMP PORTS CLOSED
INLET, PRIMARY AND SECONDARY PORTS OPEN, DUMP PORT CLOSED
VALVE SPRINGS TRANSFER VALVE
PRIMARY MANIFOLD PORT SECONDARY MANIFOLD PORT
FUEL MANIFOLD
ADAPTOR MATING FACE
DUMP PORT INLET PORT INLET PORT BODY ASSEMBLY DUMP PORT SPRING HOUSING SECONDARY MANIFOLD PORT PRIMARY MANIFOLD PORT C38659 Flow Divider and Dump Valve - Schematic
SECONDARY PRIMARY COOLING AIR SWIRL VANE C38663 Fuel Manifold Adapter and Nozzle - Cross-section
2 During engine operation, fuel drains from the dump valve and is collected in the ejector tank. As the fuel level rises, the float moves upwards, raising a lever and unseating a valve covering an orifice. Fuel from the
hydromechanical fuel control flowing through a venturi causes a pressure drop below the orifice. Fuel pressure acting on top of the orifice, combined with the pressure drop on the bottom, opens a non-return valve located on the bottom of the orifice. Fuel is then drawn from the tank through the orifice, to be conveyed by a tube to the inlet side of the fuel pump. When the tank fuel level drops, the float moves down and the orifice is covered by the valve. The non-return valve then closes, preventing fuel from the mechanical fuel control from entering the tank from the orifice. The ejector tank is vented to an airframe tank, which also collects fuel and oil from various drains on the engine.
(2) Engine Control System (a) Electronic Engine Control
The electronic engine control (EEC) (Ref. Figs. 22 and 23) is located on the left side of the front inlet case. The EEC operates in conjunction with the
mechanical fuel control unit (MFCU) and the autofeather unit (AFU) to provide control of engine power.
In EEC mode, the EEC has inputs from the Power Lever Angle (PLA), Rating Selector Switch (RSS), ambient conditions and aircraft requirements (e.g. bleed demand). From these inputs, the EEC determines the power required. The value of the power required is stored internally in the EEC and is also an output to the aircraft cockpit instrumentation where it is displayed as an equivalent torque value. The control system then adjusts fuel flow to obtain the power required and ensure it does not fluctuate.
The EEC also controls minimum power turbine speed (NPT), HP compressor rotor speed (NH) until just above flight idle, acceleration and deceleration. In addition, the EEC controls the intercompressor bleed valve (IBV) which ensures surge free transient operation.
In manual (degraded EEC) mode, the majority of the control functions are taken over by the Mechanical Fuel Control Unit (MFCU). In this mode, the MFCU controls high pressure rotor speed based on power lever angle. Monitoring and adjustment of the torque (power) produced is the responsibility of the person running the engine.
In manual mode, the intercompressor bleed valve remains controlled by the EEC and engine acceleration is usually faster than in EEC mode .
Below 30% NH (e.g. starting), fuel flow is controlled by the MFCU only. Above 30% NH, the EEC maintains closed loop control as described above.
The EEC, operating on 28 VDC, corrects and changes fuel flow through various inputs, both airframe and engine, as follows:
VENT WASTE FUEL INLET
WASTE FUEL EJECTOR TANK
MOTIVE FLOW INLET
FUEL OUTLET
C11865 Waste Fuel Ejector -3
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4ViewC38697 Electronic Engine Control -3
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4View and SchematicINDICATOR ENGINE TORQUE 1 NH1 NH2 T1.8 TORQUE 2 PAMB BLEED TORQUEMOTOR AUTOFEATHER UNIT (AFU) ELECTRONIC ENGINE CONTROL (EEC) DISCRETES TO & FROM OPPOSITE ENGINE EEC STEPPER MOTOR FUEL PUMP RVDT MECHANICAL FUEL CONTROL UNIT (MFCU) LOW PRESSURE FUEL IN N H N H Wf P3 BYPASS FLOW MOTIVE FLOW PLA CLA AIRFRAME ARINC 429 OUTPUT AUTOFEATHER RELAY LOW TORQUE LAMP AUTOFEATHER ARMED LAMP ACTUAL TORQUE TORQUE BUG COCKPIT DISPLAYS 28 VDC AUTO FAIL LAMP ARINC 429 INPUT FROM ADC
ENGINE CONTROL SYSTEM FAULT UART / ARINC MAINTENANCE DIAGNOSTICS DISCRETES CONDITION FUEL SHUT OFF LEVER
POWER LEVER RVDT PVM CLA PLA WF PAMB P1.8 T1.8 NH P3
ROTARY VARIABLE DIFFERENTIAL TRANSFORMER PROPELLER VALVE MODULE
CONDITION LEVER ANGLE
FUEL FLOW AMBIENT PRESSURE TOTAL INLET PRESSURE TOTAL INLET TEMPERATURE HIGH PRESSURE ROTOR SPEED INTERSTAGE AIR PRESSURE POWER LEVER ANGLE
PVM
PLA
PLA
FUEL FLOW
C63872 Engine Control and Electrical System - Schematic
(b) Airframe Inputs 1 Mode selector.
Manual switch: This switch selects manual (MFCU) control of the engine. 2 EEC rating selector.
Selects the required bug power rating - i.e., ATO (alternate take off), MCT (maximum continuous), CLB (maximum climb) and CRZ (maximum cruise).
3 Propeller feathered signal (feather discrete).
This signal comes from either the condition lever angle switch, manual feather switch or autofeather relay to cancel propeller ‘‘underspeed fuel governing’’ whenever the propeller is feathered.
4 Uptrim relay.
Sends uptrim signal when commanded by opposite engine autofeather control unit (AFU).
5 Engine trim switch.
Adjusts the measured power lever angle to eliminate power lever stagger due to system tolerances.
6 LRU fault select.
Maintenance activated switch controls display of EEC fault codes. 7 Propeller brake signal.
Selects NH limited APU mode operation. 8 Ground test switch.
Not used.
9 Bleed signal (2 Discrete Inputs).
Indicates bleed air extraction level and lowers thermal power limit of engine.
10 Air data computer.
Electrical signals from the computer transmit outside air temperature (OAT), altitude pressure (PALT) and indicated airspeed (IAS). These signals are normally used instead of those from engine sensors to compute and transmit a signal to the torque gage which positions the bug to control engine fuel flow. The engine sensors are used only when a fault occurs in the air data input to the EEC.
(c) Engine Inputs
1 Ambient pressure (PAMB).
Pneumatic signal to a transducer installed in the EEC. 2 Total inlet pressure (P1.8)
Pneumatic signal to a transducer installed in the EEC. This is used to generate an airspeed signal used by the control logic.
3 Total inlet temperature (T1.8).
Electrical signal from a sensor installed in the rear inlet case. 4 High pressure turbine rotor speed (NH).
Electrical signals from pulse pick-up probes installed in the accessory gearbox.
5 Torque and power turbine rotor speed (NPT).
Electrical signals from a torque sensor installed in the reduction gearbox input housing. The sensor has two coils. If the signal from No. 1 coil deviates beyond set limits, the EEC uses the signal from No. 2 coil and a fault is recorded in the EEC memory. The torque signal is modified by a characterization plug to compensate for torque shaft variations due to tolerances.
(d) EEC output
The airframe and engine inputs are processed by logic in the EEC and
compared with reference data stored in the units memory. Commands are then generated and transmitted to:
1 The MFCU stepper motor to adjust fuel flow.
NOTE: After a major EEC or EEC input failure, then stepper motor is frozen (fail fixed), holding fuel flow and power stable under steady state conditions until reversion to manual occurs. Reversion to manual is automatic when PLA is below 65 degrees (i.e. at low power), ensuring power changes during the reversion are
minimized.
2 A reference bug on the torque indicator. The position of the bug shows the actual rated engine torque for the current operating conditions. The power lever may be adjusted to bring engine torque into line with rated torque. 3 The torque indicator to show the actual torque produced by the engine.