Airworthiness Directive · Amendment 39-15501 · Boeing Model 747-200F, 747-300, 747-400, and 747-400D Series Airplanes
Boeing Model 747-200F, 747-300, 747-400, and 747-400D Series Airplanes
This AD applies to Boeing Model 747-200F, 747-300, 747-400, and 747-400D series airplanes, certificated in any category; as identified in Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008.
We are adopting a new airworthiness directive (AD) for certain Boeing Model 747-200F, 747-300, 747-400, and 747-400D series airplanes. This AD requires a detailed inspection to detect missing fasteners from the shear clip at a certain stub frame to auxiliary sill joint, and applicable related investigative and corrective actions. This AD results from reports of missing fasteners from the shear clip of the stub frame to auxiliary sill joint and cracking of the adjacent exterior skin and internal doubler. We are issuing this AD to ensure that fasteners are installed in the shear clip of the stub frame to auxiliary sill joint. Missing fasteners could result in cracks in the adjacent exterior skin and internal doubler, which can propagate and result in loss of structural integrity and sudden in-flight decompression of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
At the applicable compliance time and repeat intervals listed in Tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008; except where the service bulletin specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD: Do the inspection and applicable related investigative and corrective actions by accomplishing all the applicable actions specified in the Accomplishment Instructions of the service bulletin, except as provided by paragraph (g) of this AD.
If any crack is found during any inspection required by this AD, and Boeing Service Bulletin 747-53A2685, Revision 1, dated March 13, 2008, specifies to contact Boeing for appropriate action: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (i) of this AD.
Actions accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-53A2685, dated May 31, 2007, are considered acceptable for compliance with the corresponding actions specified in paragraph (f) of this AD.
