Airworthiness Directive · Amendment 39-17792 · Engine thrust reverser
The Boeing Company Airplanes
This AD applies to The Boeing Company airplanes, certificated in any category, identified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD, and equipped with Rolls-Royce RB211-524 engines.
(1) Model 747-200B, 747-200F, 747-300, and 747SP series airplanes, as identified in Boeing Service Bulletin 747-78-2178, Revision 1, dated August 4, 2011.
(2) Model 747-400 and 747-400F series airplanes, as identified in Boeing Service Bulletin 747-78-2180, Revision 2, dated November 11, 2011.
(3) Model 767-300 series airplanes, as identified in Boeing Service Bulletin 767-78-0096, Revision 1, dated December 10, 2009.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-200B, 747-200F, 747-300, 747SP, 747-400, and 747-400F series airplanes equipped with Rolls-Royce RB211-524 engines; and certain Model 767-300 series airplanes equipped with Rolls-Royce RB211-524 engines. This AD was prompted by multiple reports of uncommanded thrust reverser unlock events. This AD requires replacing certain relays and relay sockets, and doing wiring changes. For certain airplanes, this AD also requires installing new relay panels, and removing and installing certain components. Additionally, this AD requires, for certain airplanes, accomplishing concurrent actions, which include installing an additional locking system on the thrust reversers and modifying system wiring for in-flight fault indications of the thrust reverser system. We are issuing this AD to prevent an uncommanded thrust reverser deployment during takeoff or in flight, resulting in decreased airplane control and performance, possible runway excursions, and failure to climb.
Within 60 months after the effective date of this AD: Do the actions specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD, as applicable.
(1) For Model 747-200B, 747-200F, 747-300, and 747SP series airplanes: Replace relays and relay sockets in the P252 and P253 panels with new relays and relay sockets, and do wiring changes, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-78-2178, Revision 1, dated August 4, 2011.
(2) For Model 747-400 and 747-400F series airplanes: Install the components removed from the existing P252 and P253 panels, install new relays and relay sockets, and do wiring changes on the new P252 and P253 relay panels, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-78-2180, Revision 2, dated November 11, 2011.
(3) For Model 767-300 series airplanes: Replace relays and relay sockets in the P36 and P37 panels with new relays and relay sockets, and do wiring changes in the P33, P36, and P37 panels, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 767-78-0096, Revision 1, dated December 10, 2009.
(1) For Model 747-200B, 747-200F, 747-300, and 747SP series airplanes: Prior to or concurrently with accomplishing the actions required by paragraph (g)(1) of this AD, install an additional locking system on the thrust reversers, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-78-2156, Revision 1, dated August 30, 2001. Accomplishing this installation is a method of compliance with the installation required by paragraph (c) of AD 2000-01-05, Amendment 39-11502 (65 FR 1051, January 7, 2000).
(2) For Model 747-400 and 747-400F series airplanes identified as Group 1, 2, 3, 4, 7, 8, or 9 airplanes in Boeing Service Bulletin 747-78-2180, Revision 2, dated November 11, 2011: Prior to or concurrently with accomplishing the actions required by paragraph (g)(2) of this AD, install an additional locking gearbox on the thrust reversers of each engine and modify system wiring for in-flight fault indications of the thrust reverser system, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-78-2158, Revision 2, dated July 29, 1999.
Note 1 to paragraph (h)(2) of this AD: Paragraph (a)(1) of AD 2000-02-22, Amendment 39-11540 (65 FR 5222, February 3, 2000), refers to Boeing Service Bulletin 747-78-2158, Revision 2, dated July 29, 1999, as the appropriate source of service information for accomplishing the installation required by that paragraph.
(3) For Model 767-300 series airplanes identified as Group 2 airplanes in Boeing Service Bulletin 767-78-0096, Revision 1, dated December 10, 2009: Prior to or concurrently with accomplishing the actions required by paragraph (g)(3) of this AD, install a second locking gearbox system on the thrust reversers, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 767-78-0059, Revision 3, dated January 20, 1994.
Note 2 to paragraph (h)(3) of this AD: Paragraph (c) of AD 94-17-03, Amendment 39-8998 (59 FR 41647, August 15, 1994), refers to Boeing Service Bulletin 767-78-0059, Revision 3, dated January 20, 1994, as an appropriate source of service information for accomplishing the installation required by that paragraph.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
