1. Planning Information A. Effectivity Boeing 747 and Boeing 767 All RB211-524 Engines with Lightweight Thrust Reverser. RB211-524D4-19, 524D4-B-19, 524D4-39, 524D4-B-39, 524D4X-19, 524D4X-B-19 Propulsion Systems. RB211-524G, 524G-T, 524H, 524H-T Engines. RB211-TR525-19-A, TR525-19-B, TR526-39-A, TR526-39-B, TR528-19-A, TR528-19-B, TR529-19-A, TR529-19-B, TR530-19-A, TR530-19-B, TR532-39-A, TR532-39-B, TR533-39-A, TR533-39-B, TR534-39-A, TR534-39-B, TR537-19-A, TR537-19-B, TR537-36-A, TR537-36-B, TR538-19-A, TR538-19-B, TR538-36-A, TR538-36-B, TR541-19-A, TR541-19-B, TR541-36-A, TR541-36-B, TR542-19-A, TR542-19-B, TR542-36-A, TR542-36-B, TR556-19-A, TR556-19-B, TR557-19-A, TR557-19-B, TR558-19-A, TR558-19-B, TR559-19-A, TR559-19-B, TR560-39-A, TR560-39-B, TR561-39-A, TR561-39-B, TR562-39-A, TR562-39-B, TR563-39-A, TR563-39-B Thrust Reversers.
B. Reason A detailed investigation into the loss of a Thrust Reverser Unit (TRU) during landing has identified the reason to be a progressive detachment of TRUs fixed structure front ring rivet lines on the rear flange. This then lead to the subsequent fracture of the rivets around its forward flange. Rolls-Royce has concluded that the loss of the rivet lines was directly linked to a previous translating cowl gearbox stubshaft fracture and the subsequent repair of the fixed structure to Engine Manual repair FRS5887 (see References (1.H.)). FRS5887 instructs the replacement of the damaged section of structure, but recent stress and impact analysis utilising the latest technology and techniques indicates that rivets adjacent to the repair, and currently not replaced, are likely to have been overloaded above their elastic limit. Rivets on the structures rear ring may also have been overloaded even if there was no visible damage. It is therefore necessary to instruct the replacement of these potentially yielded rivets from units in service in order to prevent a further Thrust Reverser loss. RB211-524 LIGHTWEIGHT THRUST REVERSER - REPLACEMENT OF DAMAGED RIVETS ON THRUST REVERSER FIXED STRUCTURE - NON-MODIFICATION SERVICE BULLETIN - NON - MOD.78-AG084Printed in Great Britain



# RB.211−78−AG084 Page 1 of 8 Dec. 1/08 Nov. 6/09Furthermore, if the gearbox stubshaft fracture event was relatively severe, indicated by the structures rear ring also requiring repair to either FRS4976 or FRS6669 (see References (1.H.)), the level of overload to the structures front ring rivets is increased. A shorter reaction time is therefore required to rectify the situation when rear ring structural repairs have been embodied at the same time as FRS5887 (see References (1.H.)). Non-Modification Service Bulletin (NMSB) 78-AF573 (see References (1.H.)) was issued in September 2007 which identified thrust reverser units that had previously been repaired to FRS5887 (see References (1.H.)) and hence would have experienced a thrust reverser stubshaft fracture. The results of this survey should be used to identify which engines are subject to this Alert NMSB. Revision 1 of this NMSB was issued to include an engine mark that was unintentionally omitted. Revision 2 of this NMSB is issued to extend the time frames for Compliance. C. Compliance
ALERT Compliance is in accordance with the criteria in Table 1 and in zones as identified in Fig.1. This NMSB is anticipated to be subject to the incorporation requirements of an EASA Airworthiness Directive. D. Approval The technical content of this Non-Modification Service Bulletin was approved under the authority of Design Organisation Approval EASA.21J.035 on Nov.28/08 and re-approved on Xxx.XX/09. E. Manpower The Non-Modification Service Bulletin can only be accomplished in shop (1) Time to gain access Not applicable (2) Time to embody 40 hours (3) Time to restore to serviceable condition Not applicablePrinted in Great Britain



# RB.211−78−AG084 Page 2 Dec. 1/08 Nov. 6/09F. Material Price and Availability Not applicable G. Tooling Price and Availability Required tooling is listed in relevant removal/installation procedure, provided in References (1.H.). H. References (1) RB211-524 Reference Service Bulletins 78-AF573 Lightweight Thrust Reverser - Inspection for evidence of loose or missing rivets on thrust reverser attachment flange - Non-Modification Service Bulletin (2) Engine Manual, 78-32-00, Removal and Installation (3) Engine Manual, 78-32-00, Disassembly and Assembly (4) Engine Manual, 78-32-06-300-023, Thrust Reverser Fixed Structure - Rear Ring Assembly - Replace Damaged Rear Ring (FRS4976) - REPAIR 023 (5) Engine Manual, Task 78-32-06-300-033, Thrust reverser - Fixed structure, front ring - Repair damaged outer web at the number two and/or three gearbox positions by fitting replacement section, FRS5887 - REPAIR 033 (6) Engine Manual, Task 78-32-06-300-040, T/R fixed structure rear ring - repair damaged front flange by replacement of section, FRS6669 - REPAIR 118Printed in Great Britain



# RB.211−78−AG084 Page 3 Dec. 1/08 Nov. 6/092. Material Information
None.Printed in Great Britain



# RB.211−78−AG084 Page 4 Dec. 1/08 Nov. 6/093. Accomplishment instructions A. Procedure (1) Remove the thrust reverser unit in accordance with the following Engine Manual tasks: RB211-524D4, Engine Manual - 2RR, TASK 78-32-00-000-001-B01, Remove Thrust Reverser (Lightweight), CONFIG-2 RB211-524G/H-T, Engine Manual - 7RR, TASK 78-32-00-000-001, Remove Thrust Reverser - REMOVAL (2) Disassemble the thrust reverser unit in accordance with the following relevant Engine Manual tasks to a suitable level to allow access to rework the fixed structure front and rear ring assemblies (EIPC ref. 78-32-06, Fig/Item No. 05-570 and 05-025): RB211-524D4, Engine Manual - 2RR, TASK 78-32-00-000-000-B01, Disassemble Cold Stream Thrust Reverser System - DISASSEMBLY, CONFIG-2 RB211-524G/H-T, Engine Manual - 7RR, TASK 78-32-00-000-000-B01, Disassemble Cold Stream Thrust Reverser System - DISASSEMBLY (3) Incorporate FRS5887 Part 2 and 4.B. on the fixed structures front ring, following the instructions in the repair scheme. (4) Incorporate FRS6669 Part 2 on the fixed structures rear ring, following the instructions in the repair scheme. If FRS4976 was accomplished at the time or subsequently to the TRU gearbox stubshaft fracture then Accomplishment Instructions 3.A.(4) can be omitted. (5) Record incorporation of Non-Modification Service Bulletin on the thrust reversers data plate. (6) Assemble the thrust reverser unit in accordance with the following Engine Manual tasks: RB211-524D4, Engine Manual - 2RR, TASK 78-32-00-400-000, Assemble Cold Stream Thrust Reverser System - ASSEMBLY, CONFIG-2 RB211-524G/H-T, Engine Manual - 7RR, TASK 78-32-00-400-001, Assemble Cold Stream Thrust Reverser System - ASSEMBLY (7) Fit the thrust reverser unit to engine in accordance with the following Engine Manual tasks: RB211-524D4, Engine Manual - 2RR, TASK 78-32-00-400-000-B01, Install Thrust Reverser (Lightweight) - INSTALLATION, CONFIG-2Printed in Great Britain



# RB.211−78−AG084 Page 5 Dec. 1/08 Nov. 6/09RB211-524G/H-T, Engine Manual - 7RR, TASK 78-32-00-400-000, Install Thrust Reverser - INSTALLATION B. A record of accomplishment is required.Printed in Great Britain



# RB.211−78−AG084 Page 6 Dec. 1/08 Nov. 6/09Thrust Reverser Unit Fig.1Printed in Great Britain



# RB.211−78−AG084 Page 7 Dec. 1/08 Nov. 6/09NMSB 78-AG084 Table of Compliance Table 1Printed in Great Britain



# RB.211−78−AG084 Page 8 Dec. 1/08 Nov. 6/09