LIST OF EFFECTIVE PAGES The effective pages to this Service Bulletin are as follows: Page Revision Number Revision Date

Bulletin 1 Dec.13/12 2 Dec.13/12 3 Dec.13/12 4 Dec.13/12 5 Dec.13/12 6 Dec.13/12 7 Dec.13/12 8 Dec.13/12 Appendix 1 1 Dec.13/12 Appendix 2 1 Dec.13/12 2 Dec.13/12 3 Dec.13/12 Appendix 3 1 Dec.13/12 2 Dec.13/12**Printed in Great Britain**



# RB.211−72−AH029 Transmittal - Page 21. Planning Information A. Effectivity (1) Boeing 757 (a) RB211-535E4-37, 535E4-37/10, 535E4-37/11, 535E4-37/12, 535E4-37/14, 535E4-37/16, 535E4-37/17, 535E4-37/19, 535E4-37/20, 535E4-37/23, 535E4-37/24, 535E4-37/25, 535E4-37/39, 535E4-37/43, 535E4-37/44 Engines RB211 M05621AA, M05622AA, M05623AA M05 Modules (b) RB211-535E4-B-37, 535E4-B-37/15, 535E4-B-37/19, 535E4-B-37/20, 535E4-B-37/21, 535E4-B-37/25, 535E4-B-37/35, 535E4-B-37/39, 535E4-B-37/41, 535E4-B-37/44 Engines RB211-M05623AA, M05627AA M05 Modules (c) RB211-535E4-C-37, 535E4-C-37/43 Engines RB211 M05640AA M05 Modules (2) Tupolev TU204 RB211-535E4-B-75, 535E4-B-75/25 Engines RB211 M05623AA, M05627AA M05 Modules
B. Reason (1) Problem Due to instances of operation outside of currently published flight profiles a review of Group A part lives has been conducted. As a result of this investigation changes to the thermal profile and stresses in certain features of the LP Turbine stage 2 disc have been identified. This increase in stress level has resulted in a reduction in the cyclic life of the LP Turbine stage 2 discs. This Non-Modification Service Bulletin (NMSB) is issued to introduce reduced cyclic lives for all RB211-535E4 series engines LP Turbine stage 2 discs. The reduced cyclic lives have been designated as provisional lives until incorporated into the Time Limits Manual (TLM). The provisional lives will be added to the TLM on the 30th November 2016. ENGINE - LOW PRESSURE (LP) TURBINE STAGE 2 DISC - LIFE REDUCTION - NON-MODIFICATION SERVICE BULLETIN - NON - MOD.72-AH029**Printed in Great Britain**



# RB.211−72−AH029 Page 1 of 8 Dec.13/12 Dec.13/12Failure to comply with this NMSB will introduce a risk of exceeding the Group A part life limits and can lead to component failure. This NMSB should be reviewed together with SB 72-D365 Revision 5 or later revisions, NMSB 72-AG875 and the current published TLM. C. Description This NMSB introduces reduced (provisional) cyclic lives for the RB211-535E4 series engines LP Turbine stage 2 discs. The provisional lives and their applicable part numbers are detailed in Appendix 1. D. Compliance
ALERT Rolls-Royce recommends that the following actions are under taken on LP Turbine stage 2 discs within 6 weeks of the initial issue date of NMSB 72-AH029. For engines which will be built up during this specified time, this NMSB should not be applied. This NMSB shall be considered live six weeks after Initial issue and the instructions given in 3. Accomplishment Instructions must be followed thereafter. The LP Turbine stage 2 disc lives defined in Appendix 1, together with the lives currently published within the TLM must be utilised until the TLM is updated. On 30th November 2016 the reduced LP Turbine stage 2 disc life limits will be added to Chapter 05 of the Time Limits Manual (TLM). After this date all previously published life limits will no longer be applicable. This NMSB and in particular, the provisional life limits given in Appendix 1 are anticipated to be the subject of EASA and FAA Airworthiness Directives (AD) E. Approval The technical content of this Non-Modification Service Bulletin was approved under the authority of Design Organisation Approval EASA.21J.035 on Dec.13/12. F. Manpower Not applicable G. Material Price and Availability Not applicable**Printed in Great Britain**



# RB.211−72−AH029 Page 2 Dec.13/12 Dec.13/12H. Tooling Price and Availability Special tools are not required. I. References (1) Rolls-Royce Non-Modification Service Bulletins: (a) 72-D181 Engine - LP Turbine Rotor - Stage 2 turbine disc reduced cyclic life - Engine Management and On-wing Inspection - Non-Modification Service Bulletin (b) 72-AG875 Changes to Time Limits Manual and Aircraft Maintenance Manual resulting from changes to the RB211-535E4-B Flight Profile - Non-Modification Service Bulletin (2) Rolls-Royce Service Bulletin: 72-D365 Engine - LP turbine stage 2 Disc - Introduction of Rework to Maintain Cyclic Life (3) Time Limits Manual (TLM), Chapter 05-00-01, 05-10-01**Printed in Great Britain**



# RB.211−72−AH029 Page 3 Dec.13/12 Dec.13/122. Material Information
None**Printed in Great Britain**



# RB.211−72−AH029 Page 4 Dec.13/12 Dec.13/123. Accomplishment Instructions A. The provisional life limits detailed in Appendix 1 are to be used together with the current published TLM and the guidance given in section 3.B., 3.C. and 3.D. below by all operators to make sure necessary systems and controls are in place prior to them being published in the TLM on the 30th November 2016.

NOTE : The operating life of the LP turbine stage 2 disc may be extended by the incorporation of SB 72-D365. Artificial ageing of parts subject to life extension re-work must be conducted in accordance with SB 72-D365 Revision 5 or later revisions. B. On-Wing (1) Pre SB72-D365 Engines on-wing at the time of NMSB release may continue to use the current published applicable rework threshold life as defined in the TLM until 30th November 2016. After that date engines on-wing will be subject to the provisional rework threshold lives defined in Appendix 1 of this NMSB. (2) SB72-D365 Engines on-wing at the time of NMSB release may continue to use the current published applicable DSCLs as defined in the TLM until 30th November 2016. After that date engines on-wing will be subject to the provisional lives defined in Appendix 1 of this NMSB. (3) After release of this NMSB, should On-wing engines be removed for a shop visit, the In-shop instructions contained in section 3.C. will then become applicable.**Printed in Great Britain**



# RB.211−72−AH029 Page 5 Dec.13/12 Dec.13/12(4) It is recommended that operators should calculate their accrued life and then should compare it with the provisional lives defined in this NMSB against the applicable flight profile. Operators should then use this information to facilitate shop visit planning in order to make sure that they will comply with the provisional lives before the 30th of November 2016.
NOTE : When a disc has previously embodied SB 72-D365 Revision 4 or earlier revisions, it is necessary to review the life history and retrospectively apply the provisional rework threshold life. As defined in SB 72-D365 Revision 5 or later revisions, if the disc life at rework is found to be above the provisional rework threshold the accrued life post rework is unchanged. If the disc life at rework is found to be below the provisional rework threshold then the disc should be artificially aged in accordance with the provisional rework threshold and the accrued life should be re-calculated. Refer to example 1 given in Appendix 2 for further guidance. C. In-shop

NOTE : Overhaul refers to refurbishment where the discs are de-bladed. (1) Pre SB72-D365 LP turbine stage 2 discs Post release of this NMSB, engines that are inducted into the shop should follow the instructions defined in Fig.1, which provides guidance covering the rework or replacement of pre SB 72-D365 discs at overhaul. (2) SB72-D365 LP turbine stage 2 discs Post release of this NMSB, engines that are inducted into the shop should follow the instructions defined in Fig.1, which provides guidance covering the replacement of post SB 72-D365 discs at overhaul.
NOTE : When a disc has previously embodied SB 72-D365 Revision 4 or earlier revisions, it is necessary to review the life history and retrospectively apply the provisional rework threshold life. As defined in SB 72-D365 Revision 5 or later revisions, if the disc life at rework is found to be above the provisional rework threshold the accrued life post rework is unchanged. If the disc life at rework is found to be below the provisional rework threshold then the disc should be artificially aged in accordance with the provisional rework threshold and the accrued life should be re-calculated. Refer to example 2 given in Appendix 2 for further guidance.**Printed in Great Britain**



# RB.211−72−AH029 Page 6 Dec.13/12 Dec.13/12D. Calculations for movement between Flight Profiles

CAUTION : LIFE CALCULATIONS FOR THE MOVEMENT BETWEEN FLIGHT PROFILES OF COMPONENTS WITH MID LIFE REWORKS CAN BE CALCULATED INCORRECTLY, WHICH CAN POTENTIALLY LEAD TO COMPONENT FAILURE. IF YOU ARE NOT SURE HOW TO DO THE CALCULATION, CONTACT YOUR LOCAL ROLLS-ROYCE FIELD SERVICE OFFICE FOR ADVICE. When a disc has been operated in more than one flight profile it will be necessary to perform a movement between flight profiles calculation. See Appendix 3 for guidance and examples when necessary. Further guidance and examples can be found in the chapter 05-00-01 of the Time limits Manual.**Printed in Great Britain**



# RB.211−72−AH029 Page 7 Dec.13/12 Dec.13/12LP Turbine Stage 2 Disc Replacement Logic During Overhaul Fig.1**Printed in Great Britain**



# RB.211−72−AH029 Page 8 Dec.13/12 Dec.13/12Maximum Approved Lives of LP Turbine Stage 2 Disc The life of the following components can be extended by artificial ageing as defined in and by the incorporation of SB72-D365.
NOTE : Until the TLM is updated the pre rework provisional life will act as the rework threshold life It is permissible to rework a LP turbine stage 2 disc that has a greater cyclic life than the threshold for 'Flight Profile B, D or E' in accordance with SB72-D365. 1. Pre SB72-D365 The following LP turbine stage 2 disc lives are subject to MANDATORY NMSB 72-D181 EIPC FIG/ITEM PART NO. EFFECTIVITY 535E4 FLIGHT PROFILE PROVISIONAL PRE-REWORK THRESHOLD LIVES (FLIGHT CYCLES)
72-51-61,

01-350 UL11508, UL17141, UL18947, UL29029,

UL37352 E4 Flight Profile A 16,700 Flight Profile B 13,300 E4-B Flight Profile C 16,700 Flight Profile D Refer to NMSB 72-AG875 Flight Profile E Refer to NMSB 72-AG875 E4-C Flight Profile F 16,700 2. SB72-D365 EIPC FIG/ITEM PART NO. EFFECTIVITY 535E4 FLIGHT PROFILE PROVISIONAL POST REWORK LIVES (FLIGHT CYCLES)
72-51-61,

01-350 FW16685 FW16686, FW16687, FW16688, FW16689, E4 Flight Profile A 26,300 Flight Profile B 20,900 E4-B Flight Profile C 26,300 Flight Profile D Refer to NMSB 72-AG875 Flight Profile E Refer to NMSB 72-AG875 E4-C Flight Profile F 26,300 APPENDIX 1**Printed in Great Britain**



# RB.211−72−AH029 Appendix 1 - Page 1 of 1 Dec.13/12 Dec.13/12Revision of Artificially Aged Component Records 1. Example 1: The example RB211-E4-37 engine is on-wing with a post SB72-D365 Low Pressure Turbine Disc. It has an accrued life of 20,400 cycles whilst operating in 'Flight Profile A'. It has a further 8000 cycles remaining before it reaches the 'Flight Profile A' DSCL currently published in the TLM (28,400 cycles).

A. Step 1: Gather component life history: (1)Establish the accrued life of the disc before rework in accordance with SB72-D365:

The LP turbine stage 2 disc was operating in 'Flight Profile A' and had SB72-D365 Revision 4 embodied during its last overhaul at an accrued life of 17,500 cycles. (2)Establish whether the component life was artificially aged at rework: In accordance with the SB72-D365 revision and TLM published at the time of the rework, the disc was subject to artificial ageing to a rework threshold life of 18,100 cycles for a component operated in 'Flight Profile A'. (3)Establish the accrued life post the rework: The disc has since flown a further 2,300 cycles in 'Flight Profile A' and has a current recorded accrued life of 20,400 cycles. B. Step 2: Recalculate the accrued life of the disc to account for the new provisional lives introduced by this NMSB: (1)Compare the accrued life before rework with the provisional threshold life published in this NMSB and establish whether the disc needs to be retrospectively artificially aged to this new value:

(1) 17,500 cycles is greater than the provisional rework life of 16,700 cycles as defined in Appendix 1. (2) In accordance with SB72-D365 Revision 5 (and Appendix 1) as the life at rework was greater than the provisional rework threshold limit the disc will not be artificially aged and the rework accrued life would remain 17,500 cycles. (2)Establish the new accrued life post the rework: Adding the additional post rework 2,300 cycles means the new accrued life of the disc is 19,800 cycles. APPENDIX 2**Printed in Great Britain**



# RB.211−72−AH029 Appendix 2 - Page 1 of 3 Dec.13/12 Dec.13/12C. Step 3: Calculate the new cycles remaining of the component: In accordance with Appendix 1, the provisional life limit introduced by this NMSB reduces the post rework life limit to 26,300 cycles which means there is 6500 cycles remaining against the provisional life in Flight Profile A. D. Step 4: Apply the instructions defined in section 3.B. or 3.C as applicable: (1)As this engine is on-wing the accomplishment instructions detailed in 3.B. will need to be followed. (2)In accordance with these instructions the Engine can remain on-wing and use the existing limits defined by the current published TLM, providing the LP turbine disc will comply with the new limits defined within this NMSB before 30th of November 2016 (Note this may require the engine to complete a shop visit before this date). The information gathered and calculated in the above should be used for shop visit planning purposes. 2. Example 2: The example RB211-E4-37 engine is off wing and is to be inducted for overhaul where the LP turbine module will be refurbished (discs are debladed). It has a post SB72-D365 Low Pressure Turbine Disc. It has an accrued life of 20,400 cycles whilst operating in 'Flight Profile A'. It has a further 8000 cycles remaining before it reaches the 'Flight Profile A' DSCL currently published in the TLM (28,400 cycles). The engine has a planned build life of 6000 cycles.

A. Step 1: Gather component life history: (1)Establish the accrued life of the disc before rework: The LP turbine stage 2 disc was operating in 'Flight Profile A' and had SB72-D365 embodied during its last overhaul at an accrued life of 14,200 cycles. (2)Establish whether the component life was artificially aged at rework: In accordance with SB72-D365 Revision 4 and TLM published at the time of the rework, the disc was subject to artificial ageing to a rework threshold life of 18,100 cycles for a component operated in 'Flight Profile A'. (3)Establish the accrued life post the rework: The disc has since flown a further 2,300 cycles in 'Flight Profile A' and has a current recorded accrued life of 20,400 cycles.**Printed in Great Britain**



# RB.211−72−AH029 Appendix 2 - Page 2 Dec.13/12 Dec.13/12B. Step 2: Recalculate the accrued life of the disc to account for the new provisional lives introduced by this NMSB: (1)Compare the accrued life before rework with the provisional threshold life published in this NMSB and establish whether the disc needs to be retrospectively artificially aged to this new value:

(1) 14,200 cycles is less than the provisional rework threshold life of 16,700 cycles as defined in Appendix 1. (2) In accordance with SB72-D365 Revision 5 (and Appendix 1) as the life at rework was less than the provisional rework threshold limit the disc will be artificially aged and the rework accrued life would become 16,700 cycles. (2)Establish the new accrued life post the rework: Adding the additional post rework 2,300 cycles means the new accrued life of the disc is 19,000 cycles. C. Step 3: Calculate the new cycles remaining of the component: In accordance with Appendix 1, the provisional life limit introduced by this NMSB reduces the post rework life limit to 26,300 cycles which means there is 7300 cycles remaining against the provisional life in 'Flight Profile A'. D. Step 4: Apply the instructions defined in section 3.B. or 3.C as applicable: (1)As this engine is in the shop the accomplishment instructions detailed in 3.C. will need to be followed. (2)In accordance with these instructions and using the logic diagram in Fig.1, the new accrued life of the LP turbine stage 2 disc (19,000 cycles) plus the engine build life (6,000 cycles) equates to 25,000 cycles which will be less than the post rework life limit of 26,300 cycles. (3)Therefore the LP turbine stage 2 disc does not need to be replaced and the engine can return to service with no further action required on this component. The new accrued life should be recorded against the component records and the provisional life limits should be used in place of the current limits published in the DSCL.**Printed in Great Britain**



# RB.211−72−AH029 Appendix 2 - Page 3 Dec.13/12 Dec.13/12NOTE : The movement of LP Turbine Stage 2 discs between engine marks or published operating flight profiles requires pro-rata calculations to determine the pre-rata disc life 1. Calculations for movement of engines between flight profiles A. Calculate the Fraction of the component's Life Used (FLU) in the original flight profile monitoring procedure:

FLU = Cycles used in original flight profile monitoring procedure

---------------------------------------------------------------- Declared Life in original flight profile monitoring procedure
NOTE : It is not necessary to record a value for the FLU (it may remain as the fraction above) however if one is recorded, it should be calculated to a minimum of three decimal places. B. Calculate equivalent Cycles Since New (CSN) for the component in the new flight profile monitoring procedure.
Equivalent CSN = FLU x Declared Life in the new flight profile monitoring procedure

NOTE : Record the equivalent CSN as an integer, calculated to the next highest whole number, against the component. C. If required, calculate the cycles remaining to the Declared Life in the new flight profile monitoring procedure.
Cycles remaining = Declared Life in the new flight profile monitoring procedure - Equivalent CSN
2. Example Movement between flight profile monitoring procedures LP turbine stage 2 disc part number UL29029 (pre SB 72-D365), having originally flown 1,000 cycles in profile 'Flight Profile A', it is then moved to flight profile 'Flight Profile B' and has completed a further 14,000 cycles. It is proposed that this disc is reworked in accordance with SB 72-D365. Post rework, the engine will continue in service in 'Flight Profile B' flight profile.

A. Fraction of the component's Life Used (FLU): APPENDIX 3**Printed in Great Britain**



# RB.211−72−AH029 Appendix 3 - Page 1 of 2 Dec.13/12 Dec.13/12FLUn = Cycles used in original flight profile monitoring procedure n

----------------------------------------------------------- Declared Life in original flight profile monitoring procedure *n

FLU1 = 1000 Flight Cycles

--------------------- 16700 Flight Cycles

FLU2 = 14000 Flight Cycles

--------------------- 13300 Flight Cycles
* For pre-rework calculation this value is the applicable provisional rework threshold life. B. Total Equivalent CSN:
Total Equivalent CSN

= (FLU1 x Declared Life in the 'Flight Profile B' flight profile) + (FLU2 x Declared Life in the 'Flight Profile B' flight profile)

Total Equivalent CSN = 1000 14000 (---- X 13300 ) + (---- X 13300 ) = 14796.41 Flight Cycles 16700 13300
Rounding up gives equivalent CSN in the 'Flight Profile B' flight profile of 14797 Flight Cycles
NOTE : Accomplishment of SB 72-D365: 14797 Flight Cycles is greater than the 'Flight Profile B' provisional threshold life of 13300 (Appendix 1). However it is permissible to rework a disc that has a greater cyclic life than the threshold for 'Flight Profile B'. For this example, SB72-D365 instructs that the part will retain its existing life. C. If required, calculate the cycles remaining to the Provisional Life in the 'Flight Profile B': 20900 - 14797 = 6103 Flight Cycles remaining in profile 'Flight Profile B' (NOTE: Quoted lives are for example only)**Printed in Great Britain**



# RB.211−72−AH029 Appendix 3 - Page 2 Dec.13/12 Dec.13/12