Airworthiness Directive · Amendment 39-18210 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-100, -200B, and -200F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014.
We are superseding Airworthiness Directive (AD) 2004-13-02, which applied to certain The Boeing Company Model 747-100, -200B, and - 200F series airplanes. AD 2004-13-02 required repetitive inspections to find discrepancies in the upper and lower skins of the fuselage lap joints, and repair if necessary. This new AD adds post-repair inspections for cracking and corrosion, and repair if necessary; structural modification at the lap joints; and post-modification inspections for cracking and corrosion, and repair if necessary. This AD was prompted by an evaluation by the design approval holder (DAH) that indicates the longitudinal lap joints are subject to widespread fatigue damage (WFD). The actions mandated by this AD are necessary to reach the limit of validity (LOV). We are issuing this AD to detect and correct fatigue cracking in the upper and lower skins of the fuselage lap joints, which could result in sudden fracture and failure of a lap joint and rapid in-flight decompression of the airplane fuselage.
For airplanes identified as Groups 2 through 14 in Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014: Except as provided by paragraph (l)(3) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, do an external low frequency eddy current inspection for corrosion at the upper row of fasteners in the lap joint, and do all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(1) of this AD. Do all applicable corrective actions before further flight. Repeat the inspection at the upper row of fasteners in the lap joint thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(3) of this AD. Accomplishment of a structural modification in accordance with Part 5 of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(1) of this AD, terminates the inspection requirements of this paragraph in the area of the modification only. The actions required by paragraph (j) of this AD are still applicable in the area of the modification.
For airplanes identified as Groups 2 through 14 in Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014: Except as provided by paragraph (l)(3) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, do an internal medium frequency eddy current inspection for skin cracks at the lower row of fasteners in the lap joint, and do all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(1) of this AD. Do all applicable corrective actions before further flight. Repeat the inspection at the lower row of fasteners in the lap joint thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(3) of this AD. Accomplishment of a structural modification in accordance with Part 5 of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(1) of this AD, terminates the inspection requirements of this paragraph in the area of the modification only. The actions required by paragraph (j) of this AD are still applicable in the area of the modification.
For airplanes identified as Groups 2 through 14 in Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014: At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(2) of this AD, do a structural modification at the lap joints, and all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(1) of this AD. Do all applicable corrective actions before further flight. Accomplishment of the structural modification required by this paragraph terminates the inspections required by paragraphs (g), (h), and (k) of this AD in the area of the modification only. The actions required by paragraph (j) of this AD are still applicable in the area of the modification.
For airplanes on which the actions required by paragraph (i) of this AD have been done: At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(2) of this AD, do an internal high frequency eddy current (HFEC) inspection for cracks of the skin or existing internal doublers, and an open-hole HFEC inspection for splice strap cracks, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014. If any cracking is found, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD. Repeat the inspections of the skin, internal doublers, and splice straps thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014.
For airplanes with any new or existing external doubler repair accomplished at a lap joint and the repair doubler length is 40 inches or longer: At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(2) of this AD, do an internal HFEC inspection for cracking or corrosion of the repairs, and do all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(1) of this AD. Do all applicable corrective actions before further flight. Repeat the inspection of external doubler repairs accomplished at lap joints thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014. Accomplishment of a structural modification in accordance with Part 5 of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, except as provided by paragraph (l)(1) of this AD, terminates the inspection requirements of this paragraph in the area of the modification only. The actions required by paragraph (j) of this AD are still applicable in the area of the modification.
(1) If, during any action required by this AD, Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, specifies to contact Boeing for an inspection or modification procedure, or repair instructions: Before further flight, do the inspection, or modification, or repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(2) Where Paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2463, Revision 2, dated June 16, 2014, specifies a compliance time “after the Revision 2 date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(3) For the compliance threshold and repetitive interval calculations for inspections required by paragraphs (g) and (h) of this AD, the provisions specified in paragraphs (l)(3)(i) and (l)(3)(ii) of this AD apply regarding differential pressure.
(i) For inspections done before the effective date of this AD: Flight cycles in which the cabin differential pressure was at 2.0 pounds-per-square-inch (psi) or less need not be counted in the flight-cycle determination, provided that flight cycles with momentary spikes in cabin differential pressure above 2.0 psi were included as full pressure flight cycles. For this provision to apply, all cabin pressure records must have been maintained for each airplane. No fleet-averaging of cabin pressure is allowed.
(ii) For inspections done on or after the effective date of this AD: All flight cycles must be counted, regardless of differential pressure.
