Final rule · 2026-16504

Airworthiness Directives; The Boeing Company Airplanes

The FAA is superseding Airworthiness Directive (AD) 2018-11- 14, which applied to certain The Boeing Company Model 767-300 and -300F series airplanes with certain winglets installed. AD 2018-11-14 required high frequency eddy current (HFEC) inspections for cracking of the lower outboard wing skin and repair or modification if necessary. AD 2018-11-14 also required one of three follow-on actions: Repeating the HFEC inspections; modifying certain internal stringers and oversizing and plugging the existing fastener holes of the lower wing; or modifying the external doubler/tripler and doing repetitive post- modification inspections. This AD was prompted by reports of fatigue cracking in the lower outboard wing skin at the inboard fastener of stringer L-9.5, and the lower outboard wing skin of stringer L-6.5, on airplanes with winglets installed per Supplemental Type Certificate (STC) ST01920SE. This AD was also prompted by a determination that, for certain airplanes, the area of the lower wing skin in the vicinity of the critical inboard end fasteners of installed repair doublers must be inspected. This AD continues to require the actions in AD 2018-11-14, adds to the applicability airplanes that have had STC ST01920SE installed and the STC winglets removed, and, for certain airplanes, requires repetitive internal and external HFEC inspections of the lower outboard wing skin common to the external doubler repair at stringer L- 9.5 and repair if necessary. The FAA is issuing this AD to address the unsafe condition on these products.