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

Bulletin 1 Apr.30/13 2 Apr.30/13 3 Apr.30/13 4 Apr.30/13 5 Apr.30/13 6 Apr.30/13 7 Apr.30/13 8 Apr.30/13 9 Apr.30/13 10 Apr.30/13 11 Apr.30/13 12 Apr.30/13 13 Apr.30/13 14 Apr.30/13 15 Apr.30/13 Appendix 1 1 Apr.30/13 2 Apr.30/13**Printed in Great Britain**



# RB.211−72−AG644 Transmittal - Page 21. Planning Information A. Effectivity Boeing 777 RB211 TRENT875-17 Engines not incorporating SB72-G604 RB211 TRENT877-17 Engines not incorporating SB72-G604 RB211 TRENT884-17 Engines not incorporating SB72-G604 RB211 TRENT884B-17 Engines not incorporating SB72-G604 RB211 TRENT892-17 Engines not incorporating SB72-G604 RB211 TRENT892B-17 Engines not incorporating SB72-G604 RB211 TRENT895-17 Engines not incorporating SB72-G604
B. Reason Problem It has been identified that limitations in the drawing definition for the Trent 800 LP Turbine Bearing Support and Exhaust Case assembly (EIPC 72-52-51, 03-300, also known as the Tail Bearing Housing or TBH) may have resulted in thin wall section parts being delivered into service. A number of in-service parts have been measured and analysis of the results suggests that under certain circumstances the integrity of a thin walled part may be affected following a Fan Blade Off event. Action has been taken in new production to prevent manufacture of thin walled parts in the future, therefore this Non-Modification Service Bulletin (NMSB) will not be applicable to new part numbers. C. Description This NMSB targets two populations of LP Turbine Bearing Support and Exhaust Case assembly. The first group comprises nine assemblies which have already been measured during shop visit and subsequently shown to be below desirable limits. For this first group, the NMSB instructs a one-time rework to the LP Turbine Bearing Support and Exhaust Case assembly in accordance with SB72-G604 (see 1.I., References) at the next shop visit. ENGINE - LP TURBINE BEARING SUPPORT AND EXHAUST CASE ASSEMBLY (TAIL BEARING HOUSING)

WALL THICKNESS INSPECTION - NON-MODIFICATION SERVICE BULLETIN - NON - MOD.72-AG644**Printed in Great Britain**



# RB.211−72−AG644 Page 1 of 15 Apr.30/13 Apr.30/13The second group comprises the rest of the fleet. For this second group, the NMSB instructs a one-time in-shop inspection of the LP Turbine Bearing Support and Exhaust Case assembly for part markings, for hub to conical panel weld thickness and for hub to conical panel flange thickness (see Fig.1 and Fig.3). These measurements will be used to determine whether or not rework in accordance with SB72-G604 is required and will ensure the wall thickness in both locations is adequate for continued operation. It is recommended that the required information is recorded during the inspection in Appendix 1 (or similar form) and kept with the engine records for possible future use. Accomplishment of this NMSB must be recorded in the engine and module logbooks. D. Compliance (1) On-Wing Not applicable (2) In Shop
ALERT This Non-Modification Service Bulletin is anticipated to be the subject of an EASA/FAA Airworthiness Directive Accomplish the actions defined in Section 3., Accomplishment Instructions as follows: (a) For Engines which have an LP turbine module (Module 08) with one of the following Serial Numbers: FM0015, FM0032, FM0104, FM0114, FM9773, FM9922, FM9925, FM9950, FM9951. Accomplish the actions defined in 3., Accomplishment Instructions, Part A, by the earliest of: (i) At the next Serviceability, Check and Repair, Refurbishment or Overhaul engine shop visit (ii) By 30th June 2017. (b) For Engines which have an LP turbine module (Module 08) with any Serial Number which is NOT listed at (a), above Accomplish the actions defined in 3., Accomplishment Instructions, Part B, by the earliest of: (i) During shop visit for those engines currently in the shop where the affected part is exposed and substantial rebuild has not yet started**Printed in Great Britain**



# RB.211−72−AG644 Page 2 Apr.30/13 Apr.30/13(ii) At the next Refurbishment or Overhaul engine shop visit, or where the module is sufficiently exposed to carry out the inspection. (iii) By 31st December 2020. E. Approval The technical content of this Non-Modification Service Bulletin was approved under the authority of the EASA Design Organisation Approval No.EASA.21J.035 on Apr.29/13. F. Manpower Time to inspect: 1 hour (1 person) G. Material Price and Availabilty
None H. Tooling Price and Availability Special tools are not required I. References (1) Rolls-Royce RB211 Service Bulletins: 72-G604 Engine - Exhaust Case - Introduction of a revised LP Turbine Exhaust Case and Support Assembly featuring an increased wall thickness of LP Bearing Support flange (2) Engine Manual, 72-52-51, Cleaning (3) Engine Overhaul Processes Manual TSD 594-J, Task 70-00-00-300-363, Marking Methods (4) Standard Practices Manual, Task 70-42-11-300-001, Repair Minor Damage on Surfaces 2. Material Information
None**Printed in Great Britain**



# RB.211−72−AG644 Page 3 Apr.30/13 Apr.30/133. Accomplishment Instructions A. LP Turbine Modules with Serial Numbers listed in 1.D., Compliance, Section (2), (a): (1) Refer to Fig.1, Fig.2 and Fig.7. (2) Check the LP Turbine Bearing Support and Exhaust Case assembly (72-52-51, 03-300) part and serial numbers match those given in Fig.7 for the applicable Module Serial Number (a) If the identity markings do not match those given in Fig.7, inform your assigned Rolls-Royce service representative. (b) If the identity markings match those given in Fig.7, proceed to step (3), below. (3) Rework the LP Turbine Bearing Support and Exhaust Case assembly in accordance with Service Bulletin 72-G604 (4) Mark the part to record accomplishment of NMSB 72-AG644: (a) Refer to Fig.2. (b) Refer to Engine Overhaul Processes Manual TSD 594-J, Task 70-00-00-300-363, Marking Methods (c) Mark NMSB 72-AG644 adjacent to the part number. Use vibration-peen equipment. (5) Record the accomplishment of NMSB 72-AG644 in the engine and module logbooks. B. LP Turbine Modules with any Serial Numbers which are NOT listed in 1.D., Compliance, Section (2), (a): (1) Clean the part. Refer to Engine Manual, 72-52-51, Cleaning. (2) Check the part for markings (a) Refer to Fig.2. (b) View location of part markings for evidence of the previous accomplishment of NMSB72-AG644 (c) If there is no part marking of the previous accomplishment of NMSB72-AG644, then proceed to step (3) of these Accomplishment Instructions, below.**Printed in Great Britain**



# RB.211−72−AG644 Page 4 Apr.30/13 Apr.30/13(d) If there is part marking of the previous accomplishment of NMSB72-AG644, then: (i) Ensure that accomplishment of this NMSB has been recorded in the engine and module logbooks (ii) No further action is required (3) Measure the LP Turbine Bearing Support and Exhaust Case assembly hub to conical panel weld line thickness (a) Refer to Fig.3 and Fig.4. (b) Check that the weld dressing is smooth and continuous around the circumference of the part and check that there are no sharp changes in the profile: (i) If the weld dressing is not smooth, then lightly dress to a smooth profile, taking care to avoid thinning the material. Refer to Standard Practices Manual, Task 70-42-11-300-001, Repair Minor Damage on Surfaces. (c) Measure the thickness of the Hub to Conical Panel weld line at eight circumferential, equispaced locations, begin at the Top Dead Centre (TDC) and continue in a clockwise direction. Take five measurements at each location as follows: (i) One measurement between 11,00mm and 12,00mm (0.433in. and 0.472in.) radially outboard from the centre of the weld (position Y1). (ii) One measurement 6,00mm (0.236in.) radially outboard from the centre of the weld (position Y2). (iii) One measurement at the centre of the weld (position Y3). (iv) One measurement 6,00mm (0.236in.) radially inboard from the centre of the weld (position Y4).**Printed in Great Britain**



# RB.211−72−AG644 Page 5 Apr.30/13 Apr.30/13(v) One measurement 12,00mm (0.472in.) radially inboard from the centre of the weld (position Y5).
NOTE : Some LP Turbine Bearing Support and Exhaust Case assemblies with Part Number FK24251 or FK32232 where chemically etched at manufacture to thin the material 13mm (0.512in.) from the weld line. Ensure that the measurement at position Y1 is not taken in an etched thin area by measuring not more than 12mm (0.472in.) from the centre of the weld line. The rework specified in SB 72-G604 is effective up to 10,00mm (0.394in.) from the weld line; for this reason ensure Y1 measurements are not taken less than 11,00mm (0.433in.) from the centre of the weld line. (d) Apply the following sentencing criteria to the minimum measurement from the eight measured locations defined at (c) above: (i) Minimum thickness at positions Y1, Y2, Y3, Y4 and Y5 is equal to, or greater than, 2,52mm (0.099in.) Accept Proceed to step (4), below

(ii) Minimum thickness at position Y1 is equal to, or greater than, 2,52mm (0.099in.) and minimum thickness at positions Y2, Y3, Y4 or Y5 is less than, 2,52mm (0.099in.) Rework in accordance with SB72-G604 Proceed to step (5), below

(iii) Minimum thickness at position Y1 is less than, 2,52mm (0.099in.) Reject Proceed to step (6), below

(4) Measure the LP Turbine Bearing Support and Exhaust Case assembly Hub to Conical Panel Flange thickness (a) Refer to Fig.3, Fig.5 and Fig.6. (b) Measure the thickness 'X' of the Hub to Conical Panel at eight circumferential, equispaced locations, begin at the Top Dead Centre (TDC) and continue in a clockwise direction: (c) Apply the following sentencing criteria to the measurements from the eight locations defined at (c) above: (i) Minimum thickness is equal to, or greater than, 2,20mm (0.087in.) Accept Proceed to step (5), below**Printed in Great Britain**



# RB.211−72−AG644 Page 6 Apr.30/13 Apr.30/13(ii) The thickness at one location is less than 2,20mm (0.087in.) but is greater than, or equal to, 2,00mm (0.079in.) and at all other locations is equal to, or greater than, 2,20mm (0.087in.) Accept Proceed to step (5), below

(iii) The thickness at two locations, which are not adjacent, is less than 2,20mm (0.087in.) but is greater than, or equal to, 2,00mm (0.079in.) and at all other locations is equal to, or greater than, 2,20mm (0.087in.) Accept Proceed to step (5), below

(iv) The thickness is between 2,20mm (0.087in.) and 2,00mm (0.079in.) in more than two locations or in two adjacent locations Rework in accordance with SB72-G604 Proceed to step (5), below

(v) Minimum thickness is less than 2,00mm (0.079in.) Rework in accordance with SB72-G604 Proceed to step (5), below (5) Mark the part to record the accomplishment of the NMSB: (a) Refer to Fig.2. (b) Refer to Engine Overhaul Processes Manual TSD 594-J, Task 70-00-00-300-363, Marking Methods. (c) Mark NMSB 72-AG644 adjacent to the part number. Use vibration-peen equipment. (6) Record the accomplishment of NMSB 72-AG644 in the engine and module logbooks.**Printed in Great Britain**



# RB.211−72−AG644 Page 7 Apr.30/13 Apr.30/13Flow Chart description of NMSB 72-AG644 Fig.1 (Sheet 1 of 2)**Printed in Great Britain**



# RB.211−72−AG644 Page 8 Apr.30/13 Apr.30/13Flow Chart description of NMSB 72-AG644 Fig.1 (Sheet 2 of 2)**Printed in Great Britain**



# RB.211−72−AG644 Page 9 Apr.30/13 Apr.30/13LP Turbine Bearing Support and Exhaust Case Assembly - Location of part markings Fig.2**Printed in Great Britain**



# RB.211−72−AG644 Page 10 Apr.30/13 Apr.30/13Hub to Conical Panel weld line and flange - measurement areas Fig.3**Printed in Great Britain**



# RB.211−72−AG644 Page 11 Apr.30/13 Apr.30/13Measurement locations Y1, Y2, Y3, Y4 and Y5 on the hub to conical panel weld line at 8 circumferential locations Fig.4**Printed in Great Britain**



# RB.211−72−AG644 Page 12 Apr.30/13 Apr.30/13Hub to Conical Panel flange Measurement loation X for Hub to Conical Panel flange at 8 circumferential locations Fig.5**Printed in Great Britain**



# RB.211−72−AG644 Page 13 Apr.30/13 Apr.30/13Hub to Conical Panel Flange thickness - Sentencing criteria Fig.6**Printed in Great Britain**



# RB.211−72−AG644 Page 14 Apr.30/13 Apr.30/13Serial Nos. relating to Modules referenced in 1.,D., Compliance Fig.7**Printed in Great Britain**



# RB.211−72−AG644 Page 15 Apr.30/13 Apr.30/13Non-Modification Service Bulletin 72-AG644 Service Data Proforma

See over APPENDIX 1**Printed in Great Britain**



# RB.211−72−AG644 Appendix 1 - Page 1 of 2 Apr.30/13 Apr.30/13**Printed in Great Britain**



# RB.211−72−AG644 Appendix 1 - Page 2 Apr.30/13 Apr.30/13