Airworthiness Directive · Amendment 39-17117 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 777-200 and -300 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 777-53A0043, dated November 9, 2011.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 and -300 series airplanes. This AD was prompted by reports of fatigue cracks in the lap joints, which initiated at scribe lines that were made during production when maskant was removed from the affected skin panels during the chemical milling process. This AD requires repetitive external phased-array ultrasonic inspections to detect cracks of the affected fuselage skin lap splices in Sections 41, 43, and 44, as applicable, and repair if necessary. We are issuing this AD to detect and correct such fatigue cracking, which could grow large and cause sudden decompression and the inability to sustain limit flight and pressure loads.
Except as provided by paragraph (h)(1) of this AD, at the applicable time identified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 777-53A0043, dated November 9, 2011: Do external phased-array ultrasonic inspections to detect cracks of the affected fuselage skin lap splices in Sections 41, 43, and 44, as applicable, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0043, dated November 9, 2011. If any crack is found, before further flight, repair in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-53A0043, dated November 9, 2011; except as required by paragraph (h)(2) of this AD. Repeat the inspections of unrepaired areas thereafter at intervals not to exceed 4,200 flight cycles.
(1) Where Boeing Alert Service Bulletin 777-53A0043, dated November 9, 2011, specifies a compliance time “after the original issue date on 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 777-53A0043, dated November 9, 2011, specifies that “other approved methods” may be used to install a repair, this AD requires that the repair be done using a method approved in accordance with the procedures specified in paragraph (i) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
