Airworthiness Directive · Amendment 39-17493 · Fuselage
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.
(1) All Model 747SP airplanes.
(2) Model 747-100B SUD airplanes, line numbers 636 and 655.
(3) Model 747-300 airplanes, line numbers 692 through 695 inclusive.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 747SP series airplanes, and certain The Boeing Company Model 747-100B SUD and 747-300 series airplanes. This AD was prompted by an evaluation by the design approval holder indicating that the fuselage skin just above certain lap splice locations is subject to widespread fatigue damage. This AD requires repetitive inspections for cracking of the fuselage skin above certain lap splice locations, and repair if necessary. We are issuing this AD to detect and correct fatigue cracking of the fuselage skin, which could result in reduced structural integrity of the airplane and sudden loss of cabin pressure.
Perform external sliding probe eddy current inspections of the fuselage skin for cracking, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2854, dated September 17, 2012, except where this service bulletin specifies to contact Boeing for inspection instructions, this AD requires doing the inspection using a method approved in accordance with the procedures specified in paragraph (h) of this AD. Do the inspection at the applicable initial compliance time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2854, dated September 17, 2012, except that where this service bulletin 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.
(1) If no cracking is found during any inspection required by paragraph (g) of this AD, repeat the inspection thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2854, dated September 17, 2012.
(2) If any cracking is found during any inspection required by paragraph (g) of this AD: Before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (h) of this AD.
