P.O. Box 31, DERBY DE24 8BJ, UK Telephone: 44 (0) 1332 242424 Fax: 44 (0) 1332 249936 

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# Rol Is-Royce

TRANSMITTA The technical information contained in this document has been approved under the authority of 

## - See Planning Information, Approval.

Signed Date Nov. 4/11
N. J. Wright

RB211 TRENT 800 SERIES PROPULSION SYSTEMS NON-MODIFICATION SERVICE BULLETIN 

# ALERT

This document transmits Revision 1 to Service Bulletin RB211-72-AG456
Document History Service Bulletin Revision Status Initial Issue Sep. 9/10
Bulletin Revision 1
Remove Pages 1 to 11 of the Service Bulletin Supplement Revision Status

Incorporate Pages 1 to 19 of the Service Bulletin



# ALERT Reason for change To introduce on-wing and in-shop cold side and hot side inspection procedures to 3.B. Accomplishment Instructions. Added Fig.4 thru Fig.8. Updated 1.B. Reason, 1.D. Description, 1.1. References and titles to Fig.1 thru Fig.3. Minor non-technical changes also made.

Transmittal 

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CHECK THAT ALL PREVIOUS TRANSMIlTALS HAVE BEEN INCORPOWTED If any have not been received please advise Customer Data Services, Rolls-Royce plc, Derby, England O Rolls-Royce plc {date as above) Printed in Great BritainLIST 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 Nov.4/11 R 2 1 Nov.4/11 R 3 1 Nov.4/11 R 4 1 Nov.4/11 R 5 1 Nov.4/11 R 6 1 Nov.4/11 R 7 1 Nov.4/11 R 8 1 Nov.4/11 R 9 1 Nov.4/11 R 10 1 Nov.4/11 R 11 1 Nov.4/11 R 12 1 Nov.4/11 R 13 1 Nov.4/11 R 14 1 Nov.4/11 R 15 1 Nov.4/11 R 16 1 Nov.4/11 R 17 1 Nov.4/11 R 18 1 Nov.4/11 R 19 1 Nov.4/11**Printed in Great Britain**



# RB.211−72−AG456 Transmittal - Page 21. Planning Information A. Effectivity Boeing 777 All RB211 TRENT 875-17, 877-17, 884-17, 884B-17, 892-17, 892B-17 and 895-17 Engines.
B. Reason Cracking has been found on the head sections of two Trent 800 front combustion liners during routine inspection at shop visit. The lives of the cracked combustion liners were 1997 cycles and 7332 cycles since new. Laboratory investigation concluded that the cracking had propagated circumferentially. Analysis shows that cracking in this position could ultimately result in hot gas breakout with the potential for downstream component distress. Although there is already a Maintenance Planning Document (MPD) requirement to borescope inspect the front combustion liner, this does not cover the front combustion liner head section area. Non-Modification Service Bulletin (NMSB) 72-AG073 was initially issued in May 2009 for a once around the fleet inspection of all engines incorporating the affected type of combustor. The results from the inspection have been used to complete a numerical risk assessment which shows the crack mechanism to be age independent. Revision 1 of this NMSB is issued to introduce on-wing and in-shop cold side and hot side inspection procedures to 3.B. Accomplishment Instructions and to add relevant figures (Fig.4 thru Fig.8). R R R C. Description This NMSB is issued to instruct a repeat inspection of the front combustion liner head section for cracking and to provide acceptance limits and revised inspection intervals in the event of such cracking being found. Repeat inspection intervals have been based on current FCL inspection intervals in line with MPD requirements and NMSB 72-AF458. For convenience both hot and cold side on-wing borescope inspections are included in this NMSB - only one method is required to accomplish the NMSB intent. The hot side borescope inspection involves using the 8 borescope ports at the combustion outer case for access. The cold side borescope inspection involves removing one of the fuel spray nozzle bolts at 7 positions and using the bolt hole for access. An alternative in-shop inspection is also provided. R R R R R R ENGINE - REPEAT BORESCOPE INSPECTION OF FRONT COMBUSTION LINER HEAD SECTION NON-MODIFICATION SERVICE BULLETIN - NON - MOD.72-AG456**Printed in Great Britain**



# RB.211−72−AG456 Page 1 of 19 Sep 9/10 Nov. 4/11 RAccomplishment of this NMSB must be recorded in the engine/module log book. Provide details of any cracking found during these inspections. The details should include combustor head section life and description of the crack size(s) and circumferential location(s). The information should be returned to Rolls-Royce Technical Services via your local field service representatives. D. Compliance
ALERT This Non-Modification Service Bulletin is R the subject of an EASA Proposed Airworthiness Directive (PAD:11-038). R Carry out either R the hot side or cold side inspection specified in 3. Accomplishment Instructions. It is recommended that the inspections are aligned where possible with existing scheduled combustion liner borescope inspections. On-wing (1) All Trent 800 variants listed in 1.A. Effectivity (a) Inspect in accordance with 3.A. On-wing Accomplishment Instructions. (i) Initial inspection within 1000 cycles of the issue date of this NMSB, or within 2000 cycles since last NMSB72-AG456 inspection. R (ii) Repeat inspections at intervals not exceeding 2000 cycles since last inspection or since shop visit. In-shop (1) All Trent 800 variants listed in 1.A. Effectivity (a) Inspect in accordance with 3.B. In-shop Accomplishment Instructions at each shop visit. E. Approval The technical content of this Non-Modification Service Bulletin was approved under the authority of Design Organisation Approval EASA.21J.035 on Sep.6/10 and was re-approved on Nov.2/11. R R F. Manpower (1) Manpower 2 persons**Printed in Great Britain**



# RB.211−72−AG456 Page 2 Sep 9/10 Nov. 4/11 R(2) Time to gain access 1.5 hours (3) Time to inspect 1.5 hours (4) Time to restore to serviceable condition 1 hour R G. Material Price and Availability Not applicable. H. Tooling HU82292 Guide Tube - 1 off I. References (1) Rolls-Royce RB211 Non-Modification Service Bulletins: (a) 72-AF458 Engine - Borescope Inspection of front combustion liner inner wall (b) 72-AG073 Engine - Inspection of front combustion liner head section (2) Boeing 777 Aircraft Maintenance Manual, 70-51-00, Standard Practices, R 72-00-00, Inspection/Check, 73-13-11, Removal/Installation R (3) Trent 800 Engine Manual, 72-00-00, Inspection/Check (4) Aircraft Illustrated Parts Catalogue (AIPC), 73-13-11 R**Printed in Great Britain**



# RB.211−72−AG456 Page 3 Sep 9/10 Nov. 4/11 R2. Material Information
None**Printed in Great Britain**



# RB.211−72−AG456 Page 4 Sep 9/10 Nov. 4/11 R3. Accomplishment Instructions R A. On-Wing Accomplishment Instructions Carry out the hot side or cold side inspection as follows: R
CAUTION : IN ORDER TO REDUCE THE POTENTIAL FOR MULTIPLE ENGINE IN FLIGHT SHUTDOWN, POWER LOSS OR OTHER ANOMALIES 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. R R R R R R R R R (1) Hot side inspection: R (a) Carry out the inspection accessing via the combustion liner borescope ports. This procedure requires a flexible borescope no greater than 6 mm diameter with straight ahead near focus viewing tip. Gain access for the inspection in accordance with the following Aircraft Maintenance Manual procedures. R R R R R (i) The following Aircraft Maintenance Manual References apply for this task: R R Trent 800 Engines R Boeing 777 Aircraft Maintenance Manual, 72-00-00, Inspection/Check R Borescope inspection of combustion section R (b) Use a near focus forward view tip on the flexible borescope and insert through the guide tube HU82292 so that the tip just protrudes through the curved end. Position the tube through the first borescope position to make sure the curved end points towards the inner joint of the fuel spray nozzle heatshield tile as shown in Fig.1. R R R R R (c) Feed the borescope towards the gap between the heatshield tile inner edge and the Front Combustion Liner (FCL) inner wall. Refer to Fig.1. Inspect the FCL head, in the corner of the gap for cracking at this location. Refer to Fig.2. Slowly twist the guide tube and feed the borescope along the heatshield lip to inspect the FCL across 4 heatshield tiles (2 either side of the borescope port). R R R R R R**Printed in Great Britain**



# RB.211−72−AG456 Page 5 Sep 9/10 Nov. 4/11 R(d) Repeat the procedure for the remaining 7 borescope port positions to make sure the FCL is inspected for cracks throughout the complete 360 degrees. R R R
NOTE : As there are 8 borescope ports and 24 burners, there will be some overlap of the inspection, this will make sure no portions of the FCL are missed. R R R (e) If cracking is seen, carry out repeat inspections or engine removal in accordance with Accomplishment Instructions (3.C.) for on-wing acceptance standards of this NMSB. R R R (2) Cold side inspection: R This procedure requires a flexible borescope no greater than 4mm diameter with straight ahead viewing tip. R R (a) Prepare the engine for inspection in accordance with AMM Task 73-13-11, Removal/Installation. R R (i) Remove one of the two rearmost bolts (AIPC 73-13-11, Fig./Item No. 01-10) at Fuel Spray Nozzle (FSN) positions 1, 4, 7, 10, 16, 19 and 22. Refer to Fig.4. R R R
NOTE : Only one bolt should be removed from each FSN. This is to preserve the integrity of the FSN seal. If the integrity of the FSN seal is not preserved, then the seal must be replaced resulting in the requirement for a high power ground run. R R R R R (b) Begin the inspection at FSN position 1: R (i) Feed the borescope into the bolt hole, then along the side of the FSN. R R (ii) Once past the end of the FSN, articulate the scope to the side and feed along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly (refer to Fig.6) until the tip reaches FSN 4. Refer to Fig.4 and Fig.5. R R R R R (iii) Make sure that the borescope is fed past two FSNs and all the way to the third FSN in order to make sure of complete coverage, twisting and articulating the borescope tip to prevent it falling down in front of the FSNs. Refer to Fig.6. R R R R (iv) Gradually withdraw the borescope, inspecting the weld at the front edge of the combustion chamber inner bore for any cracks. Refer to Fig.7 and Fig.8. R R R**Printed in Great Britain**



# RB.211−72−AG456 Page 6 Sep 9/10 Nov. 4/11 R(v) Once you have reached back to the point of entry, re-insert the borescope and this time articulate the scope to the opposite side and feed along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 22. Repeat the inspection in this direction (steps (ii) to (iv) above). R R R R R R (c) Repeat the procedure detailed in steps ((b)(i) to (b)(iv)) above for the following FSN positions. R R (i) FSN position 4, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 7. Refer to Fig.4 and Fig.5. R R R R (ii) FSN position 7, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 10. Refer to Fig.4 and Fig.5. R R R R (iii) FSN position 10, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 13. Refer to Fig.4 and Fig.5. R R R R (iv) FSN position 16, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 13. Refer to Fig.4 and Fig.5. R R R R (v) FSN position 19, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 16. Refer to Fig.4 and Fig.5. R R R R (vi) FSN position 22, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 19. Refer to Fig.4 and Fig.5. R R R R (d) If cracking is seen, carry out repeat inspections or engine removal in accordance with Accomplishment Instructions for on-wing acceptance standards of this NMSB. R R R (e) Once the inspection is complete, refit the removed bolts (AIPC 73-13-11, Fig./Item No. 01-10) to each of the FSN positions. Torque the bolts to 11,5 Nm (100 lbfin) in accordance with AMM 70-51-00, Standard Practices. R R R R**Printed in Great Britain**



# RB.211−72−AG456 Page 7 Sep 9/10 Nov. 4/11 R(f) Return the aircraft to its usual condition in accordance with AMM 73-13-11, Removal/Installation. R R
NOTE : There is no requirement to accomplish Test2 - The Fuel and Oil Leak test after returning the aircraft to its usual condition. R R B. In-shop Accomplishment Instructions Carry out the hot side or cold side inspection as follows: R (1) Hot side inspection: R (a) Engines where the combustion section is to be stripped, and the FCL exposed for inspection: R R (i) Where the combustion section is to be stripped and the FCL exposed for inspection, inspection of the FCL head section in accordance with Engine Manual, 72-41-13, satisfies requirements of this NMSB. R R R R (ii) If any cracking is seen reject the FCL. R (b) Engines where strip of the combustion section is not scheduled and the FCL is not exposed for inspection. R R (i) Comply with this NMSB during the existing borescope inspection at engine induction. This procedure requires a flexible borescope no greater than 6 mm diameter with straight ahead near focus viewing tip. Use the following procedures to gain access. R R R R R (1) Trent 800 Engine Manual, 72-00-00, Inspection/Check R (ii) Use a near focus forward view tip on the flexible borescope and insert through the guide tube HU82292 so that the tip just protrudes through the curved end. Position the tube through the first borescope position to make sure the curved end points towards the inner joint of the fuel spray nozzle heatshield tile as shown in Fig.1. R R R R R R (iii) Feed the borescope towards the gap between the heatshield tile inner edge and the FCL inner wall. Refer to Fig.1. Inspect the FCL head, in the corner of the gap for cracking at this location. Refer to Fig.2. Slowly twist the guide tube and feed the borescope along the heatshield lip to inspect the FCL across 4 heatshield tiles (2 either side of the borescope port). R R R R R R R**Printed in Great Britain**



# RB.211−72−AG456 Page 8 Sep 9/10 Nov. 4/11 R(iv) Repeat the procedure for the remaining 7 borescope port positions to make sure the FCL is inspected for cracks throughout the complete 360 degrees. R R R
NOTE : As there are 8 borescope ports and 24 burners, there will be some overlap of the inspection, this will make sure no portions of the FCL are missed. R R R (v) If cracking is seen, reject the FCL. R (2) Cold side inspection: R (a) Engines where the combustion section is to be stripped, and the FCL exposed for inspection: R R (i) Where the combustion section is to be stripped and the FCL exposed for inspection, inspection of the FCL head section in accordance with Engine Manual, 72-41-13, satisfies requirements of this NMSB. R R R R (ii) If any cracking is seen reject the FCL. R (b) Engines where strip of the combustion section is not scheduled and the FCL is not exposed for inspection. R R (i) Remove one of the rearmost bolts (EIPC 73-13-11, Fig./Item No. 01-058/-088) at Fuel Spray Nozzle (FSN) positions 1, 4, 7, 10, 16, 19 and 22. Refer to Fig.4. R R R
NOTE : Only one bolt should be removed from each FSN. This is to preserve the integrity of the FSN seal. If the integrity of the FSN seal is not preserved, then the seal must be replaced. R R R R (ii) This procedure requires a flexible borescope no greater than 4mm diameter with straight ahead viewing tip. Begin the inspection at FSN position 1: R R R (1) Feed the borescope into the bolt hole, then along the side of the FSN. R R (2) Once past the end of the FSN, articulate the scope to the side and feed along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly (refer to Fig.6) until the tip reaches FSN 4. Refer to Fig.4 and Fig.5. R R R R R (3) Make sure that the borescope is fed past two FSNs and all the way to the third FSN in order to make sure of complete coverage, twisting and articulating the borescope tip to prevent it falling down in front of the FSNs. Refer to Fig.6. R R R R**Printed in Great Britain**



# RB.211−72−AG456 Page 9 Sep 9/10 Nov. 4/11 R(4) Gradually withdraw the borescope, inspecting the weld at the front edge of the combustion chamber inner bore for any cracks. Refer to Fig.7 and Fig.8. R R R (5) Once you have reached back to the point of entry, re-insert the borescope and this time articulate the scope to the opposite side and feed along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 22. Repeat the inspection in this direction (steps (2) to (4) above). R R R R R R R (c) Repeat the procedure detailed in steps (b)(ii)(1) to (4) above for the following FSN positions: R R (i) FSN position 4, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 7. Refer to Fig.4 and Fig.5. R R R R (ii) FSN position 7, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 10. Refer to Fig.4 and Fig.5. R R R R (iii) FSN position 10, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 13. Refer to Fig.4 and Fig.5. R R R R (iv) FSN position 16, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 13. Refer to Fig.4 and Fig.5. R R R R (v) FSN position 19, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 16. Refer to Fig.4 and Fig.5. R R R R (vi) FSN position 22, feeding the borescope along the annulus between the inner bore of the combustion chamber and the outer surface of the outlet guide vane case assembly until the tip reaches FSN 19. Refer to Fig.4 and Fig.5. R R R R (d) If cracking is seen, reject the FCL. R (e) Once the inspection is complete, refit the removed bolts (EIPC 73-13-11, Fig./Item No. 01-058/-088) to each of the FSN positions. Torque the bolts to 11,5 Nm (100 lbfin) in accordance with EM 70-51-00, Standard Practices. R R R R**Printed in Great Britain**



# RB.211−72−AG456 Page 10 Sep 9/10 Nov. 4/11 RC. On-wing Acceptance Standards (1) Circumferential cracking. (a) Examine the front combustion liner head section for circumferential cracking in the area immediately forward of the inner wall attaching weld as shown in Fig.1, Fig.2 and Fig.3. The fly-on and rejection criteria are shown in Table 1.
CUMULATIVE CRACK LENGTH (see NOTES) ACTION

No cracking Accept No action required Cumulative crack length up to 150 mm (up to 2 heatshields) Accept Repeat inspection at intervals no more than 250 cycles

Cumulative crack length 150 mm to 300 mm (up to 4 heatshields) Accept Repeat inspection at intervals no more than 100 cycles

Cumulative crack length 300 mm to 450 mm (up to 6 heatshields) Accept Remove the engine within 50 cycles

Cumulative crack length 450 mm to 900 mm (up to 12 heatshields) Accept Remove the engine within 5 cycles

Cumulative crack length greater than 900 mm (more than 12 heatshields) Reject Remove the engine immediately

Table 1
NOTE : Count the total length of all circumferential cracks seen during inspection. The width of the heatshield tiles at the inner wall diameter is approximately 75 mm. Refer to Fig.3. D. A record of accomplishment is required.**Printed in Great Britain**



# RB.211−72−AG456 Page 11 Sep 9/10 Nov. 4/11 RR

Hot Side Inspection Route - View Through Borescope (A) and Location of Cracks R Fig.1 R**Printed in Great Britain**



# RB.211−72−AG456 Page 12 Sep 9/10 Nov. 4/11 RR

Example of Hot Side Front and Side Views Showing Area of Cracking R Fig.2 R**Printed in Great Britain**



# RB.211−72−AG456 Page 13 Sep 9/10 Nov. 4/11 RExample of Cracking from Hot Side R with Heatshields Removed Fig.3**Printed in Great Britain**



# RB.211−72−AG456 Page 14 Sep 9/10 Nov. 4/11 RR

Cold Side inspection access FSN position R Fig.4 R**Printed in Great Britain**



# RB.211−72−AG456 Page 15 Sep 9/10 Nov. 4/11 RR

Cold Side Inspection Borescope Inspection Route R Fig.5 R**Printed in Great Britain**



# RB.211−72−AG456 Page 16 Sep 9/10 Nov. 4/11 RR

Cold Side Inpsection Region to be Inspected R Fig.6 R**Printed in Great Britain**



# RB.211−72−AG456 Page 17 Sep 9/10 Nov. 4/11 RR

Location of Cracking R Fig.7 R**Printed in Great Britain**



# RB.211−72−AG456 Page 18 Sep 9/10 Nov. 4/11 RR

Example of Cracking from Cold Side R Fig.8 R**Printed in Great Britain**



# RB.211−72−AG456 Page 19 Sep 9/10 Nov. 4/11 R 

### Head Section

FSN Location Crack Inner Wall