Airworthiness Directive · Amendment 39-16284 · Fuselage
The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-300, 747SR, and 747SP Series 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 Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009.
Note 1: Airplanes having line number 629, 635, 637, 650, 666, 667, 673, 675, 683, 713, 750, or 810 are Group 5 airplanes.
The FAA is superseding an existing airworthiness directive (AD), which applies to certain Model 747 airplanes. That AD currently requires repetitive inspections to detect cracking in certain fuselage skin lap joints, and repair if necessary. This new AD expands the inspection area in the existing AD, adds a modification of certain lap joints, and adds certain post-repair inspections of the lap joints. Accomplishing the modification ends the repetitive inspections required by the existing AD for the length of lap joint that is modified. This AD results from a structural review of affected skin lap joints for widespread fatigue damage. We are issuing this AD to prevent fatigue cracking in certain lap joints, which could result in rapid depressurization 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.
For airplanes identified in Boeing Service Bulletin 747-53-2367, dated December 18, 1991: Prior to the accumulation of 22,000 full pressure flight cycles (or, if the external skin panel of an affected lap joint has been replaced, prior to the accumulation of 22,000 full pressure flight cycles since skin replacement), or within 1,000 landings after July 13, 1994 (the effective date of AD 94-12-04), whichever occurs later, perform an external surface high frequency eddy current (HFEC) inspection of the skin around the upper row of fasteners, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53-2367, dated December 18, 1991; Boeing Service Bulletin 747-53-2367, Revision 1, dated January 27, 1994; Boeing Alert Service Bulletin 747-53A2367, Revision 2, dated October 30, 2008; or Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009. As of the effective date of this AD, only Revision 3 may be used.
(1) If no crack is found, repeat the inspection thereafter at intervals not to exceed 3,000 full pressure flight cycles until the inspections required by paragraph (h) of this AD are done.
(2) If any crack is found, accomplish paragraphs (g)(2)(i) and (g)(2)(ii) of this AD.
(i) Prior to further flight, perform an open hole HFEC inspection to detect cracking in the upper row fastener holes between the adjacent frames, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-53-2367, dated December 18, 1991; Boeing Service Bulletin 747-53-2367, Revision 1, dated January 27, 1994; Boeing Alert Service Bulletin 747-53A2367, Revision 2, dated October 30, 2008; or Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009. Prior to further flight, repair any crack found, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.
Note 2: Guidance on repairing cracking can be found in Chapter 53-30-03 of the Boeing 747 Structural Repair Manual.
(ii) Repeat the inspection required by paragraph (g) of this AD thereafter at intervals not to exceed 3,000 full pressure flight cycles until the inspections required by paragraph (h) of this AD are done.
For all airplanes: Do initial and repetitive HFEC inspections for cracks of lap joints in Sections 41, 42, 44, and 46, by doing all the actions, including all applicable related investigative and corrective actions, specified in the Accomplishment Instructions of Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009, except as provided by paragraph (l) of this AD. Do the inspections at the applicable times specified in paragraph 1.E. of Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009, except as required by paragraph (k) of this AD. Do all applicable related investigative and corrective actions before further flight. Accomplishing the inspections required by this paragraph ends the repetitive inspections required by paragraph (g) of this AD. Do the actions required by paragraph (h) of this AD until the modification required by paragraph (j) of this AD is done.
(i) For areas on which a lap joint repair was installed and the repair doubler is greater than or equal to 40 inches long: Do initial and repetitive internal HFEC inspections for cracks, as required by paragraph (h) of this AD, by doing all the applicable actions, including applicable corrective actions, specified in the Accomplishment Instructions of Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009, except as provided by paragraph (l) of this AD. Do the inspection and corrective actions at the times specified in paragraph 1.E. of Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009, except as required by paragraph (k) of this AD.
Before the accumulation of 30,000 total flight cycles or within 3,000 flight cycles after the effective date of this AD, whichever occurs later: Modify the applicable lap joints in Sections 41 and 42 by doing all the actions specified in the Accomplishment Instructions of Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009, except as required by paragraph (l) of this AD. Accomplishing this modification terminates the repetitive inspection requirements of this AD for the length of lap joint that is modified.
Where Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009, specifies compliance times “from the date on the original issue of this service bulletin [12/18/91],” this AD requires compliance within the specified compliance time after July 13, 1994 (the effective date of AD 94-12-04). Where Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009, specifies compliance times “after the date on Revision 2 of this service bulletin [10/30/08],” this AD requires compliance within the specified compliance time after the effective date of this AD.
(l) Where Boeing Service Bulletin 747-53A2367, Revision 3, dated January 15, 2009, specifies to contact Boeing for repair or modification instructions: Before further flight, repair or modify using a method approved in accordance with the procedures specified in paragraph (m) of this AD.
