Airworthiness Directive · Amendment 39-18363 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-100, -100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes; certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2494, Revision 1, dated January 9, 2015.
We are superseding Airworthiness Directive (AD) 2005-01-09, which applied to certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes. AD 2005-01-09 required a one-time detailed inspection for discrepancies of the frame web and inner chords on the forward edge frame of the number 5 main entry door cutout, and corrective action if necessary. This new AD adds repetitive high frequency eddy current (HFEC) inspections for cracking of the frame inner chords (forward and aft), and corrective action if necessary. This AD was prompted by additional cracking found in the same area after completion of the one-time detailed inspection. We are issuing this AD to detect and correct discrepancies of the frame web and inner chords, which could result in cracking, subsequent severing of the frame, and consequent rapid depressurization of the airplane.
Do the applicable actions specified in paragraphs (g)(1), (g)(2), (g)(3), and (g)(4) of this AD, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2494, Revision 1, dated January 9, 2015, except as required by paragraph (h)(2) of this AD.
(1) At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2494, Revision 1, dated January 9, 2015, except as required by paragraph (h)(1) of this AD: Do a detailed inspection for nicks, scratches, or gouges of the Station 2231 frame inner chords, forward and aft, at stringer 26 at the edge and side of the inner chords.
(2) At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2494, Revision 1, dated January 9, 2015, except as required by paragraph (h)(1) of this AD: Do a surface high frequency eddy current (HFEC) inspection for cracks of the frame inner chords, forward and aft.
(3) Based on the findings from the inspections specified in paragraphs (g)(1) and (g)(2) of this AD, do all applicable corrective actions, before further flight.
(4) Repeat the HFEC inspection specified in paragraph (g)(2) of this AD at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2494, Revision 1, dated January 9, 2015.
(1) Where Boeing Alert Service Bulletin 747-53A2494, Revision 1, dated January 9, 2015, specifies a compliance time “after the release of Revision 1 of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Alert Service Bulletin 747-53A2494, Revision 1, dated January 9, 2015, specifies to contact Boeing for repair instructions: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
