AD 2020-21-17 Prompted By Reports Of Bolt Rotation In The Engine Drag Fitting Joint And Fastener Heads

The FAA is superseding Airworthiness Directive (AD) 2018-16-05, which applied to certain The Boeing Company Model 757 airplanes.

AD 2018-16-05 required repetitive inspections for skin cracking and shim migration at the upper link drag fittings, diagonal brace cracking, and fastener looseness; and applicable on-condition actions. This AD retains the actions required by AD 2018-16-05, reduces the compliance times for certain inspections, and adds repetitive inspections at certain fastener hole locations and applicable on-condition actions. This AD was prompted by reports of bolt rotation in the engine drag fitting joint and fastener heads; an inspection of the fastener holes revealed that cracks were found in the skin. This AD was also prompted by a report of multiple cracks in the drag fitting at fastener holes found during an inspection required by AD 2018-16-05. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective January 14, 2021.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2018-16-05, Amendment 39-19345 (83 FR 38250, August 6, 2018) (“AD 2018-16-05”). AD 2018-16-05 applied to certain The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes. The NPRM published in the Federal Register on December 17, 2019 (84 FR 68822). The NPRM was prompted by reports of bolt rotation in the engine drag fitting joint and fastener heads; an inspection of the fastener holes revealed that cracks were found in the skin. The NPRM was also prompted by a report of multiple cracks found in the drag fitting at fastener holes during inspections required by AD 2018-16-05. The NPRM proposed to continue to require repetitive inspections for skin cracking and shim migration at the upper link drag fittings, diagonal brace cracking, and fastener looseness; and applicable on-condition actions. The NPRM also proposed to reduce the compliance times for certain inspections and add repetitive inspections at certain fastener hole locations and applicable on-condition actions. The FAA is issuing this AD to address cracking in the wing upper skin and forward drag fittings, which could lead to a compromised upper link and reduced structural integrity of the engine strut.

FMI: www.regulations.gov