Airworthiness Directive · Amendment 39-18412 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-100, -200B, -200C, -200F, -300, -400, -400D, and -400F series airplanes; certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-100, -200B, -200C, -200F, -300, -400, - 400D, and -400F series airplanes. This AD was prompted by reports of significant fuselage skin damage at certain parts of the dorsal fairing, due to wear from the dorsal fairing. This AD requires repetitive detailed inspections for wear and cracks of the fuselage skin under the dorsal fairing, and related investigative and corrective actions if necessary. This AD also requires repetitive post-repair external surface high frequency eddy current inspections of the blended areas of the skin and detailed inspections of the unrepaired areas, and related investigative and corrective actions if necessary. We are issuing this AD to detect and correct fuselage skin damage of the dorsal fairing area, which could result in skin cracking and consequent depressurization of the airplane.
At the applicable time specified in tables 1 and 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014, except as provided by paragraph (j)(1) of this AD, do a detailed inspection of the fuselage skin under the dorsal fairing for wear or cracks, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014, except as provided by paragraph (i) of this AD and except as required by paragraph (j)(2) of this AD. Do all applicable related investigative and corrective actions at the time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014. Repeat the applicable inspections of the fuselage skin thereafter at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014.
At the applicable time specified in tables 4 and 5 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014, except as provided by paragraph (j)(1) of this AD, do an external surface high frequency eddy current inspection of the blended areas of the skin and a detailed inspection of the unrepaired areas, and do all applicable related investigative and corrective actions, in accordance with Part 8 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014, except as provided by paragraph (i) of this AD and except as required by paragraph (j)(2) of this AD. Do all applicable related investigative and corrective actions at the time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014. Repeat the applicable inspections of the blended areas of the skin thereafter at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014. Accomplishing the inspections required by this paragraph does not terminate the inspections required by paragraph (g) of this AD.
Tables 3, 6, and 7 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014, specify post-modification airworthiness limitation inspections in compliance to 14 CFR 25.571(a)(3) at the modified locations, which support compliance with 14 CFR 121.1109(c)(2) or 129.109(b)(2). As airworthiness limitations, these inspections are required by maintenance and operational rules. It is therefore unnecessary to mandate them in this AD. Deviations from these inspections require FAA approval, but do not require an alternative method of compliance.
(1) Where Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014, specifies a compliance time “after the Original Issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Although Boeing Alert Service Bulletin 747-53A2876, dated October 22, 2014, specifies to contact Boeing for repair data, and specifies that action as “RC” (Required for Compliance), this AD requires repair before further flight using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
