# Rolls-Royce Alert Non-Modification Service Bulletin 72-AK451: Revision 1

- Rights: © Rolls-Royce plc. Filed by the FAA in regulations.gov docket FAA-2021-1164, the docket of AD 2022-08-16. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Rolls-Royce Alert Non-Modification Service Bulletin 72-AK451](https://openairdocs.org/service-documents/rolls-royce/72-ak451.md)
- Title as filed: Rolls-Royce Trent 1000 Alert NMSB 72-AK451 R1
- Pages: 28
- PDF: https://openairdocs.org/files/sha256/91/c5/91c54b59ceff06f16b6649285b221cd023aeb6ff0c355156fb2380b8c9bbe5e9
- Page: https://openairdocs.org/service-documents/rolls-royce/72-ak451/file/91c54b59ceff

## Text

Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

This document transmits Revision 1 to Service Bulletin TRENT1000-72-AK451
Document History
Service Bulletin Revision Status Supplement Revision Status
Initial Issue Nov.14/19
Bulletin Revision 1
Remove Incorporate Reason for change
Pages 1 to 21 of the
Service Bulletin
Pages 1 to 22 of the
Service Bulletin
To update 1.A. Effectivity,
1.C. Description, 1.D.
Compliance, 1.E. Approval,
1.H. Tooling Price and
Availability, 1.I.
References, 3.
Accomplishment Instructions
and Appendix 2.
All pages of
Appendix 1
Page 1 and 2 of
Appendix 1
To update 1.A. Effectivity,
1.C. Description, 1.D.
Compliance, 1.E. Approval,
1.H. Tooling Price and
Availability, 1.I.
References, 3.
Accomplishment Instructions
and Appendix 2.
Printed in Great Britain
Jul.15/21
TRENT 1000 SERIES PROPULSION SYSTEMS NON-MODIFICATION SERVICE BULLETIN
ALERT TRENT 1000 72−AK451
Transmittal - Page 1 of 3
Date
ALERT
CHECK THAT ALL PREVIOUS TRANSMITTALS HAVE BEEN INCORPORATED 
If any have not been received please advise Customer Data Services, Rolls-Royce plc, Derby, England 
©Rolls-Royce plc (date as above) Printed in Great Britain

### Page 2

All pages of
Appendix 2
Page 1 of Appendix 2 To update 1.A. Effectivity,
1.C. Description, 1.D.
Compliance, 1.E. Approval,
1.H. Tooling Price and
Availability, 1.I.
References, 3.
Accomplishment Instructions
and Appendix 2.
Printed in Great Britain
TRENT 1000 72−AK451
Transmittal - Page 2

### Page 3

LIST OF EFFECTIVE PAGES
The effective pages to this Service Bulletin following incorporation of Revision
1 are as follows:
Page Revision Number Revision Date
Bulletin
R 1 1 Jul.15/21
R 2 1 Jul.15/21
R 3 1 Jul.15/21
R 4 1 Jul.15/21
R 5 1 Jul.15/21
R 6 1 Jul.15/21
R 7 1 Jul.15/21
R 8 1 Jul.15/21
R 9 1 Jul.15/21
R 10 1 Jul.15/21
R 11 1 Jul.15/21
R 12 1 Jul.15/21
R 13 1 Jul.15/21
R 14 1 Jul.15/21
R 15 1 Jul.15/21
R 16 1 Jul.15/21
R 17 1 Jul.15/21
R 18 1 Jul.15/21
R 19 1 Jul.15/21
R 20 1 Jul.15/21
R 21 1 Jul.15/21
R 22 1 Jul.15/21
Appendix 1
R 1 1 Jul.15/21
R 2 1 Jul.15/21
Appendix 2
R 1 1 Jul.15/21
Printed in Great Britain
TRENT 1000 72−AK451
Transmittal - Page 3

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1. Planning Information
A. Effectivity
(1) BOEING 787
AllR TRENT 1000-AE3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-CE3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-D3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-G3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-H3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-J3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-K3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-L3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-M3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-N3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-P3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-Q3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
AllR TRENT 1000-R3 Engines not incorporating Rolls-Royce Service Bulletin
72-K571.
R
R
ENGINE - IP COMPRESSOR (IPC) SHAFT - BORESCOPE INSPECTION OF THE FRONT AIR SEAL -
NON-MODIFICATION SERVICE BULLETIN - MOD.72-AK451
Printed in Great Britain
TRENT 1000 72−AK451
Page 1 of 22
Nov 14/19
Jul.15/21R
TRENT 1000 SERIES
SERVICE BULLETIN

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(2) AIRBUS A330
AllR TRENT 7000-72 Engines not incorporating Rolls-Royce Service Bulletin
72-K570.
R
R
AllR TRENT 7000-72C Engines not incorporating Rolls-Royce Service Bulletin
72-K570.
R
R
B. Reason
(1) Problem
Cracking of the front air seal on IP Compressor (IPC) shaft assembly
(72-32-31, 01-450, Part Number KH18436) has been identified during strip
of a flight test vehicle. Subsequent inspections have identified two
further examples of cracked front air seal on in-service engines. These
cracks could propagate and have the potential to lead to in-flight events.
(2) Safety Intent
The safety intent of this Non-Modification Service Bulletin (NMSB) is to
identify and remove cracked components from service which, if not
accomplished, could lead to high energy debris release and a potentially
hazardous condition.
C. Description
This NMSB instructs the procedures for the initial inspection and repeats of an
in-situ borescope inspection of the IP Compressor shaft assembly (72-32-31,
01-450, Part Number KH18436) at a specific area between the fourth (rearmost)
seal fin of the IP Compressor Shaft Assembly front air seal and the IP
Compressor Stage 1 disc. This inspection procedure uses a standard 4mm
borescope accessing the IP Compressor Stage 1 area through the Engine Section
Stator (ESS) vanes. This inspection can be performed in shop and on-wing. Where
intervals allow, this inspection can be performed on-wing concurrently with:
BOEING 787 aircraft: AMM Task DMC-B787-A-R72-00-00-46A-280C-A, IP
Compressor Stag e 1 - Front Surface of the Blade Root Dovetail and Rotor
Disc Post (With a Borescope).
AIRBUS A330 aircraft: AMM TASK 72-00-00-290-848-A,R Special Detailed
Inspection of the Intermediate Pressure Compressor Stag e 1 - Front Surface
of the Blade Root Dovetail and Rotor Disc Post (with a Borescope).
In both cases, access can alternatively be gained using the method
described in the applicable AMM Task.
Accomplishment of this NMSB should be recorded in accordance with local NMSB
tracking system procedures. A copy of the completed Appendix 1 or a similar
form should be used to capture results along with photographic/video recording.
Printed in Great Britain
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Revision 1 of this NMSB introduces an additional method of in-shop compliance,
various typographical improvements and amends the effectivity to Trent 1000
engines not incorporating SB 72-K571 and Trent 7000 engines not incorporating
SB 72-K570.
R
R
R
R
D. Compliance
This Non-Modification Service Bulletin is anticipated to be the subject of an
EASA Airworthiness Directive.
This Non-Modification Service Bulletin is the subject of EASA Airworthiness
Directive 2019-0282 and FAA Airworthiness Directive 2020-20-07. It is
anticipated that these will be up-issued following this revision.
R
R
R
(1) IN-SHOP
ALERT
(a) Inspect the IP Compressor Shaft Assembly in accordance with Section
3.A Accomplishment Instructions at engine shop visit, including those
engines currently in-shop at time of issue of this NMSB.
NOTE : A shop visit is defined as the time from engine removal from
wing for the purpose of a visit to a Maintenance, Repair &
Overhaul (MRO) facility until the time of dispatch of the
engine(s) from the MRO facility to the operator. Any engine
that is in such condition at the date of issue of this NMSB is
considered to be In-shop.
(b) A previous accomplishment of Service Bulletin 72-K452, Service
Bulletin 72-K618
R
R or Technical Variance TV207889 may be considered as
an acceptable means of compliance for the inspection set by Section
1.D.(1)(a).
(2) ON-WING
ALERT
(a) Inspect the IP Compressor Shaft Assembly in accordance with Section
3.B Accomplishment Instructions as per the following schedule:
(i) Initial inspection to be completed before 500 cycles (IP
Compressor Shaft Assembly cycles since new) or within 100
cycles of initialR issue date of this NMSB, whichever is later.
(ii) Repeat inspections to be completed at intervals not exceeding
200 cycles.
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(b) For IP Compressor Shaft Assemblies of greater than 700 cycles (IP
Compressor Shaft Assembly cycles since new) at time of initialR issue
of this NMSB, inspect the IP Compressor Shaft Assembly in accordance
with Section 3.B Accomplishment Instructions as follows:
(i) Initial inspection to be completed within 50 cycles from
initialR issue of this NMSB.
(ii) Repeat inspection to be completed at intervals not exceeding
200 cycles.
(c) For IP Compressor Shaft Assemblies of greater than 1000 cycles (IP
Compressor Shaft Assembly cycles since new) at time of initialR issue
of this NMSB, inspect the IP Compressor Shaft Assembly in accordance
with Section 3.B Accomplishment Instructions as follows:
(i) Initial inspection to be completed within 25 cycles from
initialR issue of this NMSB or before 1st December 2019,
whichever is sooner.
(ii) Repeat inspection to be completed at intervals not exceeding
200 cycles.
(d) A previous accomplishment of Service Bulletin 72-K452, Service
Bulletin 72-K618
R
R or Technical Variance TV207889 In-shop or On-wing may
be considered as an acceptable means of compliance for the initial
inspection set by paragraphs (a)(i), (b)(i) or (c)(i) of Section
1.D.(2).
(e) Accomplishment of this NMSB In-shop (Section 1.D.(1)) may be
considered as an acceptable means of compliance for the initial or
repeat inspection set by paragraphs (a)(i)/(ii), (b)(i)/(ii) or
(c)(i)/(ii) of Section 1.D.(2).
NOTE : Accomplishment of this NMSB In-shop before 300 cycles (IP
Compressor Shaft Assembly cycles since new) may be taken as an
additional one-time inspection. An additional initial
inspection as per Section 1.D.(2).(a) is required to initiate
the repeat inspection regime.
E. Approval
NMSB 72-AK451 was approved by Rolls-Royce on Jul. 2/21.R The technical content
of this documentR is approved under the authority of the DOA ref. EASA.21J.065.
Printed in Great Britain
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F. Manpower
(1) In-Shop
(a) Time to gain access
30 minutes (2 persons) - Estimated
(b) Time to inspect
45 minutes (2 persons) - Estimated
(c) Time to restore to serviceable condition
30 minutes (2 persons) - Estimated
(2) On-Wing
(a) Time to gain access
30 minutes (2 persons) - Estimated
(b) Time to inspect
45 minutes (2 persons) - Estimated
(c) Time to restore to serviceable condition
30 minutes (2 persons) - Estimated
G. Material Price and Availability
Not applicable.
H. Tooling Price and Availability
(1) Flexible video-capable borescope, with a forward-view 0.157in (4 mm)
diameter lens (STD-7028)
(2) Immobiliser - LP Compressor (HU44525-1/SPL-8907)
(3) Inlet Protective Mat (HU55142-1/SPL-9039)
(4) Engine Fan Cover (98K1010H005-000/SPL-8837)
(5) Engine Exhaust Cover (98K1010H006-000/SPL-8836)
(6) Rotor 1 Borescope Guide Tube (RRT108139/SPL-16443) or locally sourced
borescope guide tube - OPTIONAL
(7) OMat 150 (Acetone) or OMat 1/40 (Isopropyl Alcohol) - OPTIONAL
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(8) OMat 582 (Ultrafine Scotch Brite) - OPTIONAL
(9) Delivery tube for OMat 150 (Acetone) or OMat 1/40 (Isopropyl Alcohol) -
OPTIONAL
(10) Adhesive tape (OMat 283 or OMat 256) - OPTIONAL
(11) IP Turning Tool - (Trent 1000 - SPL-7771/RRT042712 or Trent 7000 -
RRT095945)
R
R
(12) Syringe (locally sourced) - OPTIONALR
I. References
(1) Aircraft Maintenance Manual (AMM):
(a) BOEING 787
(i) DMC-B787-A-R72-00-00-46A-280C-A, Intermediate Pressure
Compressor Stag e 1 - Front Surface of the Blade Root Dovetail
and Rotor Disc Post (with a Borescope) - Special Detailed
Inspection
(ii) DMC-B787-A-R72-00-00-01A-950A-A, Turn the Intermediate Pressure
System - Standard Practices
(b) AIRBUS A330
(i) AMM TASK 72-00-00-290-848-A,R Special Detailed Inspection of the
Intermediate Pressure Compressor Stag e 1 - Front Surface of the
Blade Root Dovetail and Rotor Disc Post (with a Borescope)
(ii) AMM TASK 72-00-00-910-801-A, Turn the Intermediate Pressure
System - Standard Practices
(2) Rolls-Royce Non-Modification Service Bulletins:R
(a) 72-K452
(i) ENGINE - IP COMPRESSOR (IPC) SHAFT BORESCOPE INSPECTION OF THE
FRONT AIR SEAL - NON-MODIFICATION SERVICE BULLETIN
R
R
(b) 72-K618R
(i) ENGINE - INTERMEDIATE PRESSURE COMPRESSOR SHAFT FRONT SEAL -
FLUORESCENT PENETRANT INSPECTION - NON-MODIFICATION SERVICE
BULLETIN
R
R
R
Printed in Great Britain
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(3) Technical Variance (TV):R
(a) TV207889R
(i) INSPECTION OF IPC DRUM FRONT SEAL AND IPC DISC STAGE 1 FOR
POTENTIAL CRACKING
R
R
(4) Airworthiness Directives:R
(a) European Union Aviation Safety Agency (EASA)R
(i) 2019-0282, ATA 72 - Engine - Intermediate Pressure Compressor
Shaft Assembly - Inspection
R
R
(b) Federal Aviation Authority (FAA)R
(i) 2020-20-07, Rolls-Royce Deutschland Ltd and Co KG (Type
Certificate previously held by Rolls-Royce plc): Amendment
39-21263; Docket No. FAA-2020-0293; Project Identifier
MCAI-2019-00122-E.
R
R
R
R
(5) Rolls-Royce Service Bulletins:R
(a) 72-K570R
ENGINE - IP COMPRESSOR SHAFT - INTRODUCTION OF AN IP COMPRESSOR STAGES
1 TO 8 ROTOR SHAFT ASSEMBLY FEATURING REVISED FRONT SEAL GEOMETRY
R
R
(b) 72-K571R
ENGINE - IP COMPRESSOR SHAFT - INTRODUCTION OF AN IP COMPRESSOR STAGES
1 TO 8 ROTOR SHAFT ASSEMBLY FEATURING REVISED FRONT SEAL GEOMETRY
R
R
Printed in Great Britain
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2. Material Information
None
Printed in Great Britain
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3. Accomplishment Instructions
A. In-Shop
(1) Use the borescope equipment to do a visual inspection of the front air
seal of the IP Compressor Shaft Assembly (72-32-31, 01-450).
(a) Assemble the applicable flexible video-capable borescope.
(b) If using a borescope guide tube:
(i) Carefully put the guide tube between the LP Compressor blades,
through the ESS vanes and stop just before the cavity in front
of the IP Compressor Stage 1 blades. Refer to Fig.1.
It is recommended that access is gained at Top Dead Centre (TDC)
to facilitate the borescope positioning into the engine.
The Variable Inlet Guide Vanes (VIGV) can prevent access from the
front of the engine. If the VIGV do prevent access, manually
actuate the VIGV mechanism until a clear path to the IP Compressor
Stage 1 blades is seen from the front of the engine.
(ii) Attach the borescope guide tube to the engine with adhesive
tape (OMat 283 or OMat 256).R
(iii) Carefully put the borescope through the borescope guide tube,
until the borescope tip is into the cavity in front of the IP
Compressor Stage 1 blades. Refer to Fig.1.
(c) If not using a borescope guide tube:
(i) Carefully put the borescope between the LP Compressor blades,
through the ESS vanes and into the cavity in front of the IP
Compressor Stage 1 blades. Refer to Fig.1.
It is recommended that access is gained at Top Dead Centre (TDC)
to facilitate the borescope positioning into the engine.
The Variable Inlet Guide Vanes (VIGV) can prevent access from the
front of the engine. If the VIGV do prevent access, manually
actuate the VIGV mechanism until a clear path to the IP Compressor
Stage 1 blades is seen from the front of the engine.
Printed in Great Britain
TRENT 1000 72−AK451
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(d) Slowly turn the IP system.
CAUTION : WHEN TURNING THE IP SYSTEM, ENSURE THAT THE ROTATION OF
THE BLADES IS AWAY FROM THE BORESCOPE TIP (FOR EXAMPLE
COUNTER-CLOCKWISE, AFT LOOKING FORWARDS). IF THE SYSTEM
IS TURNED TOWARDS THE BORESCOPE THEN THERE IS THE
POTENTIAL FOR TIP CRASH OR JAMMING OF THE IP SYSTEM.
CAUTION : MAKE SURE THAT THE BORESCOPE TIP IS NOT IN THE PATH OF
THE BLADES WHEN YOU TURN THE ENGINE. IF THE BORESCOPE
AND THE BLADES TOUCH, DAMAGE TO THE BLADES OR BORESCOPE
COULD OCCUR. THE GUIDE TUBE AND BORESCOPE SHOULD NOT BE
INSERTED INTO THE ENGINE UNTIL THE ENGINE HAS COOLED TO
WITHIN THE BORESCOPE MANUFACTURERS RECOMMENDATION.
(i) Use an applicable wrench to rotate the Hexagon drive on the IP
Turning tool (Trent 1000 - SPL-7771/RRT042712 or Trent 7000 -
RRT095945)
R
R to slowly turn the IP system away from the borescope
tip (for example counter-clockwise, aft looking forwards).
(e) Perform a full 360 degree visual inspection of the surface between the
fourth (rearmost) seal fin of the IP Compressor Shaft Assembly front
air seal (FIN 4 in Fig.2) and the IP Compressor Stage 1 disc (IPC1
ROTOR in Fig.2). Refer to Fig.2 for the expected view through the
borescope.
(i) Concentrate on looking for cracks which run at 90 degrees to
the seal fin (Forward to Aft of the engine). If doubt exists
over the disposition of an observation, assume a crack is
present.
NOTE : TO ACCOUNT FOR 360 DEGREES, EITHER USE THE IP COMPRESSOR
STAGE 1 DISC DRAIN HOLES (QTY.2, LOCATED ADJACENT TO EACH
OTHER) TO START AND FINISH THE INSPECTION, OR COUNT THE
PASSAGE OF 35 IP COMPRESSOR STAGE 1 BLADE ROOTS.
(ii) To assist in sentencing crack-likeR features in the inspection
area it is permissible to clean the suspected area using the
processes outlined in Appendix 2. Once cleaned the inspection
can be repeated starting again from Step 3.A.(1).(b).
(f) Acceptance Standards
(i) If cracking is identified on the front air seal of the IP
Compressor Shaft Assembly (72-32-31, 01-450):
(1) Make a photographic/video record of the finding.
Printed in Great Britain
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(2) REJECT the Engine (see NOTE below)
NOTE : To assist in sentencing crack-like features in the
inspection area it is permissible to clean the
suspected area using the processes outlined in
Appendix 2. Once cleaned the inspection can be
repeated starting again from Step 3.A.(1).(b).
(ii) If no cracking is identified the Front Air seal of the IP
Compressor Shaft Assembly (72-32-31, 01-450):
(1) ACCEPT the Engine
(g) After completion of the borescope inspection, carefully remove the
borescope equipment and the Rotor 1 Borescope Guide Tube (if used).
(h) Record accomplishment of this Non-Modification Service Bulletin in the
module log card and the engine logbook against EIPC Ref 72-32-31,
01-450.
(i) A copy of the completed Appendix 1 or a similar form should be
used to capture results.
B. On-Wing
WARNING : YOU MUST BE CAREFUL WHEN YOU WORK ON THE ENGINE AFTER THE ENGINE
IS SHUT DOWN. THE ENGINE CAN STAY HOT FOR ALMOST ONE HOUR. DO
NOT TOUCH HOT PARTS WITHOUT THE APPLICABLE GLOVES. HOT PARTS CAN
CAUSE INJURIES TO PERSONNEL.
CAUTION : IN ORDER TO REDUCE THE POTENTIAL FOR MULTIPLE ENGINE IN-FLIGHT
SHUTDOWN, POWER LOSS, OR OTHER ANOMALY DUE TO MAINTENANCE ERROR,
ROLLS-ROYCE RECOMMENDS THAT OPERATORS AVOID PERFORMING
MAINTENANCE ON MULTIPLE ENGINES INSTALLED ON THE SAME AIRCRAFT
AT THE SAME TIME. IF IT IS NOT POSSIBLE TO AVOID MAINTENANCE ON
MORE THAN ONE ENGINE AT THE SAME TIME, ROLLS-ROYCE RECOMMENDS
THAT ADDITIONAL CONTROLS ARE APPLIED IN ORDER TO ENSURE THAT
MAINTENANCE TASKS HAVE BEEN COMPLETED AS DEFINED. MAINTENANCE
GUIDELINES SHOULD BE REVISED, WHERE POSSIBLE, TO PROMOTE THIS
RECOMMENDATION.
(1) Prepare the aircraft for maintenance:
(a) For BOEING 787 aircraft:
Prepare the engine for inspection in accordance with
DMC-B787-A-R72-00-00-46A-280C-A, Intermediate Pressure Compressor
Stag e 1 - Front Surface of the Blade Root Dovetail and Rotor Disc Post
(with a Borescope) - Special Detailed Inspection.
Printed in Great Britain
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(b) For AIRBUS A330 aircraft:
Prepare the engine for inspection in accordance with AMM Task
72-00-00-290-848-A, Special Detailed Inspection of the Intermediate
Pressure Compressor Stag e 1 - Front Surface of the Blade Root Dovetail
and Rotor Disc Post (with a Borescope), 3. Job Set-up.
(2) Procedure:
Use the borescope equipment to do a visual inspection of the front air
seal of the IP Compressor Shaft Assembly (KH18436):
(a) Assemble the applicable flexible video-capable borescope.
(b) Carefully put the borescope into the engine to view the area
identified in Fig.2.
For access through the engine inlet and LP Compressor fan blades,
refer to Fig.1. It is recommended that access is gained at Top Dead
Centre (TDC) to facilitate the borescope positioning into the engine.
A Borescope Guide Tube may be used to facilitate the positioning of
the borescope, refer to Section 3.A.(1)(b) for guidance on how to
install the guide tube.
For access through the Outlet Guide Vanes (OGV) using a guide tube (if
performed concurrently with IP Compressor Stage 1 blade inspections)
refer to Fig.3 and applicable Aircraft Maintenance Manual inspection
task.
(c) Slowly turn the IP system.
CAUTION : WHEN TURNING THE IP SYSTEM, ENSURE THAT THE ROTATION OF
THE BLADES IS AWAY FROM THE BORESCOPE TIP (I.E.
COUNTER-CLOCKWISE, AFT LOOKING FORWARDS). IF THE SYSTEM
IS TURNED TOWARDS THE BORESCOPE THEN THERE IS THE
POTENTIAL FOR TIP CRASH OR JAMMING OF THE IP SYSTEM.
CAUTION : MAKE SURE THAT THE BORESCOPE TIP IS NOT IN THE PATH OF
THE BLADES WHEN YOU TURN THE ENGINE. IF THE BORESCOPE
AND THE BLADES TOUCH, DAMAGE TO THE BLADES OR BORESCOPE
COULD OCCUR. THE GUIDE TUBE AND BORESCOPE SHOULD NOT BE
INSERTED INTO THE ENGINE UNTIL THE ENGINE HAS COOLED TO
WITHIN THE BORESCOPE MANUFACTURERS RECOMMENDATION.
(i) When required, turn the Intermediate Pressure system in
accordance with the applicable current maintenance procedures.
(1) For BOEING 787 aircraft, Refer to
DMC-B787-A-R72-00-00-01A-950A-A, Turn the Intermediate
Pressure System - Standard Practices.
R
R
R
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(2) For AIRBUS A330 aircraft, Refer to AMM TASK
72-00-00-910-801-A, Turn the Intermediate Pressure System -
Standard Practices.
R
R
R
(d) Perform a full 360 degree visual inspection of the surface between the
fourth (rearmost) seal fin of the IP Compressor Shaft Assembly front
air seal (FIN 4 in Fig.2) and the IP Compressor Stage 1 disc (IPC1
ROTOR in Fig.2). Refer to Fig.2 for the expected view through the
borescope.
(i) Concentrate on looking for cracks which run at 90 degrees to
the seal fin (Forward to Aft of the engine). If doubt exists
over the disposition of an observation, assume a crack is
present.
NOTE : TO ACCOUNT FOR 360 DEGREES, EITHER USE THE IP COMPRESSOR
STAGE 1 DISC DRAIN HOLES (QTY.2, LOCATED ADJACENT TO EACH
OTHER) TO START AND FINISH THE INSPECTION, OR COUNT THE
PASSAGE OF 35 IP COMPRESSOR STAGE 1 BLADE ROOTS.
(ii) To assist in sentencing crack like features in the inspection
area it is permissible to clean the suspected area using the
processes outlined in Appendix 2. Once cleaned the inspection
can be repeated starting again from Step 3.B.(2).(b).
(e) Acceptance Standards
(i) If cracking is identified on the front air seal of the IP
Compressor Shaft Assembly (KH18436):R
(1) Make a photographic/video record of the finding. Capture this
information in Appendix 1 (or similar).
(2) REJECT the Engine (see NOTE below)
NOTE : To assist in sentencing crack like features in the
inspection area it is permissible to clean the
suspected area using the processes outlined in
Appendix 2. Once cleaned the inspection can be
repeated starting again from Step 3.B.(2).(b).
(ii) If no cracking is identified the Front Air seal of the IP
Compressor Shaft Assembly (KH18436):R
(1) ACCEPT the Engine.
(f) After completion of the borescope inspection, carefully remove the
borescope equipment and the Rotor 1 Borescope Guide Tube (if used).
Printed in Great Britain
TRENT 1000 72−AK451
Page 13
Nov 14/19
Jul.15/21R
TRENT 1000 SERIES
SERVICE BULLETIN

### Page 17

(g) Remove the IP Turning tool in accordance with applicable current
maintenance procedures:
(i) For BOEING 787 aircraft, refer to
DMC-B787-A-R72-00-00-01A-950A-A, Turn the Intermediate Pressure
System - Standard Practices.
R
R
R
(ii) For AIRBUS A330 aircraft, Refer to AMM TASK 72-00-00-910-801-A,
Turn the Intermediate Pressure System - Standard Practices.
R
R
(3) Close Up:
(a) For BOEING 787 aircraft:
Close up the engine in accordance with
DMC-B787-A-R72-00-00-46A-280C-A, Intermediate Pressure Compressor
Stag e 1 - Front Surface of the Blade Root Dovetail and Rotor Disc Post
(with a Borescope) - Special Detailed Inspection, E. Put the Airplane
Back to its Usual Condition.
(b) For AIRBUS A330 aircraft:
Close up the engine in accordance with AMM Task 72-00-00-290-848-A,
Special Detailed Inspection of the Intermediate Pressure Compressor
Stag e 1 - Front Surface of the Blade Root Dovetail and Rotor Disc Post
(with a Borescope), 5. Close-up.
(4) Record the accomplishment of this NMSB in accordance with local NMSB
tracking system procedures.
(a) A copy of the completed Appendix 1 or a similar form should be used to
capture results.
Printed in Great Britain
TRENT 1000 72−AK451
Page 14
Nov 14/19
Jul.15/21R
TRENT 1000 SERIES
SERVICE BULLETIN

### Page 18 (OCR)

Rolls-Royce  TRENT 1000 SERIES  SERVICE BULLETIN
VIGV
IPC1
des0001794
Borescope routing through the Engine inlet to the IP Compressor Shaft Assembly Stage
1 Front Cavity
Fig.1
Nov 14/19  TRENT 1000 72-AK451
R Jul.15/21  Page 15
© Rolls-Royce pic

### Page 19 (OCR)

Rolls-Royce  TRENT 1000 SERIES  SERVICE BULLETIN
Л
11/10/2019 16:52  Printed in Great Britain
IPC1
ROTOR
FIN 4
INSPECTION AREA
des0001795
Expected Borescope View of Inspection Area (front air seal on the IP Compressor
Shaft Assembly)
Fig.2
Nov 14/19  TRENT 1000 72-AK451
R Jul.15/21  Page 16
© Rolls-Royce plc

### Page 20

des0001796
BORESCOPE
OGV ASSEMBLY
GUIDE TUBE
A−A
A
A
IP COMPRESSOR
ROTOR BLADE
STAGE 1VIGV
ESS
BORESCOPE
Alternative inspection route (if concurrent with IP Compressor Stage 1 blade
inspection)
Fig.3
Printed in Great Britain
TRENT 1000 72−AK451
Page 17
Nov 14/19
Jul.15/21R
TRENT 1000 SERIES
SERVICE BULLETIN

### Page 21 (OCR)

Rolls-Royce  TRENT 1000 SERIES  SERVICE BULLETIN
Printed in Great Britain
HOOS
SYRINGE
SAFETY
CABLE/DELIVERY
TUBE
ADHESIVE
TAPE
L  des0001846
Example of locally manufactured cleaning tool
Fig.4
Nov 14/19  TRENT 1000 72-AK451
R Jul.15/21  Page 18
C Rolls-Royce pic

### Page 22 (OCR)

R Rolls-Royce  TRENT 1000 SERIES  SERVICE BULLETIN
2.5 mm dia
PLASTIC TUBE
TAPE
SCOTCH BRITE
des0001847
Example of locally manufactured cleaning tool.
Fіg.5
Nov 14/19  TRENT 1000 72-AK451
R Jul.15/21  Page 19
© Rolls-Royce p/c

### Page 23 (OCR)

Rolls-Royce  TRENT 1000 SERIES  SERVICE BULLETIN
Printed in Great Britain
FIN 4
(BACK FACE)
INCONCLUSIVE
INDICATION
des0001848
Example of inconclusive indication on the back of Fin 4 of the IP Compressor Front
Seal.
Fіg.6
Nov 14/19  TRENT 1000 72-AK451
R Jul. 15/21  Page 20
© Rolls-Royce plc

### Page 24 (OCR)

Rolls-Royce  TRENT 1000 SERIES  SERVICE BULLETIN
CLEANING
TOOL
INCONCLUSIVE
INDICATION
FIN 4
(BACK FACE)
des0001849
Same inconclusive indication on the back of Fin 4 of the IP Compressor Front Seal
just prior to cleaning, and example of how to position the cleaning tool.
Fig.7
Nov 14/19  TRENT 1000 72-AK451
R Jul. 15/21  Page 21
© Rolls-Royce p/c

### Page 25 (OCR)

Rolls-Royce  TRENT 1000 SERIES  SERVICE BULLETIN
CLEANING  Printed in Great Britain
TOOL
LOCATION OF INITIAL
INCONCLUSIVE
INDICATION
FIN 4
(BACK FACE)
des0001850
Initial inconclusive indication on the back of Fin 4 of the IP Compressor Front Seal
now cleaned away, indicating no crack present.
Fig.8
Nov 14/19  TRENT 1000 72-AK451
R Jul. 15/21  Page 22
© Rolls-Royce p/c

### Page 26

This form (or similar) to be completed for every engine/component inspected.
Results to be recorded within your local NMSB tracking system(s).
APPENDIX 1
Printed in Great Britain
TRENT 1000 72−AK451
Appendix 1 - Page 1 of 2
Nov 14/19
Jul.15/21R
TRENT 1000 SERIES
SERVICE BULLETIN

### Page 27 (OCR)

Rolls-Royce  TRENT 1000 SERIES  SERVICE BULLETIN
Feedback Sheet NMSB 72-AK451
Overhaul Base (if  Printed in Great Britain
applicable)
Operator
Engine Type/Mark/Rating
(Trent 1000 TEN / 7000)
Date of Inspection
Engine Serial Number
Engine Hours Since New
Engine Cycles Since New
Module Serial Number
EIPC Ref / Part Number  72-32-31, 01-450 / KH18436
Component Serial Number
Component Hours Since
New (It different from
Engine)
Component Cycles Since
New
(If different from Engine)
Inspection result (accept/reject) and comments (provide images if 'Reject')
L  des0001797
Nov 14/19  TRENT 1000 72-AK451
R Jul. 15/21  Appendix 1 - Page 2
© Rolls-Royce p/c

### Page 28

1. Use the processes outlined below to clean the affected area(s) of the IP
Compressor Shaft Assembly (72-32-31, 01-450, Part Number KH18436).R See Fig.6 to
Fig.8 for an example of the cleaning process.
A. Locally manufacture a cleaning tool to deliver OMat 150 (Acetone) or OMat
1/40 (Isopropyl Alcohol) to OMat 582 (Ultrafine Scotch Brite).
(1)See Fig.4 and Fig.5 for examples of locally-manufactured cleaning tools.
B. Secure the locally manufactured cleaning tool t oa4m mo r6m m flexible
borescope using OMat 283 (Adhesive Tape) or OMat 256 (Adhesive Tape).
NOTE : A 4 MM BORESCOPE MAY OPTIONALLY BE USED INSTEAD O FA6M MB U TI SA
NON-PREFERRED ALTERNATIVE .A6M M BORESCOPE OFFERS GREATER RIGIDITY
WHICH HELPS WITH THE POSITIONING AND CLEANING STEPS.
C. Insert the borescope, with the locally manufactured cleaning tool attached,
into the engine. A locally manufactured borescope guide tube may be used to
aid the process.
D. Locate the area(s) to be cleaned.
E. Load the syringe with sufficient OMat 150 (Acetone) or Omat 1/40 (Isopropyl
Alcohol) to perform this task.
F. Attach the loaded syringe to the locally manufactured cleaning tool.
G. Gently move the borescope back and forth ensuring contact between the
locally manufactured cleaning tool and the area to be cleaned while
simultaneously delivering OMat 150 (Acetone) or OMat 1/40 (Isopropyl
Alcohol) via the loaded syringe.
H. Remove the borescope tool from the engine.
I. Inspect the cleaned area (using Step 3.A.(1) if In-Shop or Step 3.B.(2) if
On-Wing) to make sure debris/residue has been removed. Repeat steps B thru
H to remove any remaining debris/residue if required.
APPENDIX 2
Printed in Great Britain
TRENT 1000 72−AK451
Appendix 2 - Page 1 of 1
Nov 14/19
Jul.15/21R
TRENT 1000 SERIES
SERVICE BULLETIN

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