Airworthiness Directive · Amendment 39-17597 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, and 747SR series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, - 200F, -300, -400, -400D, -400F, and 747SR series airplanes. This AD was prompted by reports of cracking at the aft upper corner of the main entry door (MED) 5 cutout. This AD requires inspecting for the presence of repairs and measuring the edge margin at certain fastener locations around the upper aft corner of the door cutout, inspecting for any cracking of the fuselage skin assembly and bear strap in the aft upper corner area of the door cutout, and repairing or modifying the fuselage skin assembly and bear strap if necessary. We are issuing this AD to detect and correct cracking of the skin and bear straps at the aft upper corner of the MED 5 cutout, which could result in in-flight depressurization.
Except as specified in paragraph (h)(1) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012: Do a detailed inspection for the presence of repairs at the aft upper corner of the MED 5 cutout, and measure the edge margin at certain fastener locations around the corner of the door cutout, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012.
(1) If a repair is found: Before further flight, inspect or change the repair, using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
(2) If no repair is found, except as specified in paragraph (h)(1) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012: Do detailed and high frequency eddy current (HFEC) inspections for any cracking of the fuselage skin assembly and bear strap in the aft upper corner area of the door cutout, as applicable, and do all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, except as required by paragraph (h)(2) of this AD. Do all applicable corrective actions before further flight. If no cracking is found: Before further flight, install a preventative modification, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, except as required by paragraph (h)(2) of this AD.
(i) Options provided in Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, for accomplishing the applicable corrective action are acceptable for the corresponding requirements of paragraph (g)(2) of this AD, provided that the inspections and preventative modification are done at the applicable times in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012.
(ii) Options provided in Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, for accomplishing the preventative modification when no cracking is found are acceptable for the corresponding requirements of paragraph (g)(2) of this AD, provided that the inspections and preventative modification are done at the applicable times in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012.
(1) Where Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, specifies compliance times “after the original issue date of this service bulletin,” this AD requires compliance within the specified compliance times “after the effective date of this AD.”
(2) Where Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, specifies to contact Boeing for appropriate action: Before further flight, do the action using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
The post-repair or post-modification inspections specified in table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, are not required by this AD.
Note 1 to paragraph (i) of this AD: The post-repair or post-modification inspection specified in table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, may be used in support of compliance with section 121.1109(c)(2) or 129.109(b)(2) of the Federal Aviation Regulations (14 CFR 121.1109(c)(2) or 14 CFR 129.109(b)(2)). The corresponding actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2839, dated November 6, 2012, are not required by this AD.
