Airworthiness Directive · Amendment 39-17685 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes; certificated in any category; as identified in Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. This AD was prompted by a report of a disbonded doubler and a skin crack in section 41 of the fuselage, and multiple reports of cracked or missing fastener heads. This AD requires repetitive inspections for cracking of the fuselage skin, discrepant fasteners, and for disbonds at the doublers; and related investigative and corrective actions if necessary. For certain airplanes, this AD also requires a terminating repair for repair doublers. We are issuing this AD to prevent rapid decompression and loss of structural integrity of the airplane due to such disbonding and subsequent cracking of the skin panels.
At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, except as required by paragraphs (i)(1) and (i)(3) of this AD: Do the applicable inspections (including detailed, high frequency eddy current (HFEC), and low frequency eddy current (LFEC)) for any cracking of the fuselage skin, for discrepant fasteners, and for disbonds at the doublers; and do all applicable related investigative and corrective actions in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, except as provided by paragraph (i)(2) of this AD. Repeat the applicable inspections thereafter at intervals not to exceed those specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012. Do all applicable related investigative and corrective actions at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012. Options provided in Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2011, for accomplishing the disbond inspection are acceptable for the corresponding requirements of this paragraph provided that the inspection is done at the applicable times in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2011.
(1) Replacing a skin panel, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, is an acceptable alternative to doing the structural repair manual (SRM) skin panel repairs and the repetitive skin panel inspections specified in tables 1, 2, and 3 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, for only the skin panel that has been replaced.
(2) Accomplishment of the terminating repair identified in tables 4 and 5 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, terminates the repetitive inspections identified in tables 4 and 5 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, for only the area on which the terminating repair has been done.
For airplanes identified in tables 4 and 5 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012: At the applicable compliance time specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, do the terminating action for the repair doubler, including doing an open hole HFEC inspection for skin cracks at the fastener holes common to the inspection area and an inspection for disbond of the internal doubler; and as applicable, replacing the existing external repair doubler with a new extended external repair doubler, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, except as provided by paragraph (i)(2) of this AD. Accomplishment of the terminating action identified in tables 4 and 5 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, terminates the repetitive inspections identified in tables 4 and 5 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, for only areas on which the terminating action has been done.
This paragraph specifies exceptions to certain instructions in Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012.
(1) Where Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, specifies a compliance time after the “original issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, specifies to contact Boeing for special repair instructions, this AD requires using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
(3) The Condition column of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2747, Revision 2, dated February 22, 2012, refers to certain conditions “as of the original issue date of this service bulletin.” This AD, however, applies to the airplanes with the specified condition as of the effective date of this AD.
