Airworthiness Directive · Amendment 39-11701 · Boeing Model 777 Series Airplanes
Boeing Model 777 Series Airplanes
Model 777 series airplanes having line numbers 1 through 119 inclusive, except line numbers 94, 102, 104, and 118; certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing 777 series airplanes, that requires a one- time inspection to detect cracking of the fastener holes common to the upper wing skins and trailing edge panels of both wings, and corrective actions, if necessary. This amendment also requires coldwork of the fastener holes and installation of new or serviceable fasteners. This amendment is prompted by a report indicating that fatigue cracks have been found in the upper wing skin of both wings. The actions specified by this AD are intended to prevent fatigue cracking of the upper wing skin, which could result in reduced structural integrity of the wing.
To prevent fatigue cracking of the upper wing skin, which could result in reduced structural integrity of the wing, accomplish the following:
(a) Prior to the accumulation of 16,000 total flight cycles or 40,000 total flight hours, whichever occurs earlier, perform a one-time eddy current inspection to detect cracking of the fastener holes common to the upper wing skins and trailing edge panels of both wings, in accordance with Boeing Alert Service Bulletin 777-57A0022, dated August 26, 1999.
(b) If any cracking is detected during the inspection required by paragraph (a) of this AD, prior to further flight, oversize the fastener hole and perform additional eddy current inspections to detect cracking of the fastener holes until all cracking is no longer detectable by means of eddy current inspection. Perform the actions in accordance with Boeing Alert Service Bulletin 777-57A0022, dated August 26, 1999. Prior to further flight, oversize the fastener hole an additional 1/32-inch minimum and measure the starting hole diameter and edge margin of the fastener hole, in accordance with the alert service bulletin.
(1) If the fastener hole diameter or the edge margin of any fastener hole is not within the limits specified in the alert service bulletin, prior to further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate, or a Boeing Company Designated Engineering Representative who has been authorized by the FAA to make such findings. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.
(2) If the fastener hole diameter and edge margin of all the fastener holes are within the limits specified in the alert service bulletin, prior to further flight, accomplish the requirements of paragraph (c) of this AD.
(c) If no cracking is detected during the eddy current inspection required by paragraph (a), or the fastener hole diameter and edge margin of all the fastener holes are within the limits required by paragraph (b) of this AD, prior to further flight, coldwork the fastener holes and install new or serviceable fasteners, in accordance with Boeing Alert Service Bulletin 777-57A0022, dated August 26, 1999.
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
