Airworthiness Directive · Amendment 39-18327 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SR, and 747SP series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SR, and 747SP series airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that certain fuselage skin lap joints are subject to widespread fatigue damage (WFD). This AD requires repetitive post-modification inspections for cracking of the skin or internal doubler along the edge fastener rows of the modification, and repair if necessary. We are issuing this AD to detect and correct fatigue cracking in certain fuselage skin lap joints, which could result in rapid depressurization of the airplane.
For airplanes identified as Groups 1 through 3, 7, and 8 in Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014: Except as provided by paragraph (m) of this AD, at the applicable time specified in table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, do internal detailed and surface high frequency eddy current (HFEC) inspections for cracks in the skin and internal doubler along the edge fastener rows of the modification, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014. In unrepaired areas, repeat the internal detailed and surface HFEC inspections for cracks in the skin or internal doubler along the edge fastener rows of the modification thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014.
For airplanes identified as Groups 4 through 6, and 9 through 11, in Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, with external doublers installed as specified in Boeing Service Bulletin 747-53-2272: Except as provided by paragraph (m) of this AD, at the applicable time specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, do external detailed, low frequency eddy current (LFEC), and HFEC inspections for cracks in the skin and external doubler, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014.
For airplanes with no crack findings during the inspections required by paragraph (h) of this AD: Do the applicable actions required by paragraphs (i)(1) and (i)(2) of this AD.
(1) For airplanes with less than 15,000 flight cycles since stringer 6 external doublers were installed, as specified in Boeing Service Bulletin 747-53-2272: At the applicable intervals specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, in unrepaired areas, repeat the external detailed and LFEC inspections for cracks in the skin, and the external detailed and HFEC inspections for cracks in the external doubler, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014.
(2) For airplanes with 15,000 or more flight cycles since the stringer 6 external doublers were installed, as specified in Boeing Service Bulletin 747-53-2272: At the applicable intervals specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, in unrepaired areas, do external detailed and LFEC inspections for cracks in the skin; and do internal and external detailed and HFEC inspections for cracks in the skin and external doubler; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014.
For airplanes identified as Groups 4 through 6, and 9 through 11, in Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, with external doublers installed as specified in Boeing Alert Service Bulletin 747-53A2367: Except as provided by paragraph (m) of this AD, at the applicable time specified in table 5 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, do internal detailed and surface HFEC inspections for cracks in the skin and internal doubler along the edge fastener rows of the modification, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014. In unrepaired areas, repeat the internal detailed and surface HFEC inspections for cracks in the skin or internal doubler along the edge fastener rows of the modification thereafter at the applicable interval specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014.
For airplanes identified as Groups 12 and 13 in Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014: Except as provided by paragraph (m) of this AD, at the applicable time specified in table 6 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, do internal detailed and surface HFEC inspections for cracks in the skin and internal doubler along the edge fastener rows of the modification, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014. In unrepaired areas, repeat the internal detailed and surface HFEC inspections for cracks in the skin or internal doubler along the edge fastener rows of the modification thereafter at the applicable interval specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014.
If any cracking is found during any inspection required by this AD: Before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2367, Revision 5, dated July 8, 2014, specifies a compliance time “after the Revision 5 date of this service bulletin,” this AD requires compliance within the specified compliance time “after the effective date of this AD.”
