Airworthiness Directive · Amendment 39-19225 · Wings
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 737-300 and -500 series airplanes, certificated in any category, with blended winglet kits installed in accordance with Supplemental Type Certificate (STC) ST01219SE.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-300 and -500 series airplanes. This AD was prompted by a report indicating that fatigue cracks were found in the lower wing skin of an airplane with winglets installed. This AD requires repetitive inspections for cracking of the lower wing skin, and repair if necessary. We are issuing this AD to address the unsafe condition on these products.
Within 18 months after the effective date of this AD: Do a detailed inspection for cracking of the lower wing skin external surface at the stringer L-5 location on the left and right wings, in accordance with the Accomplishment Instructions of Aviation Partners Boeing Service Bulletin AP737C-57-002, dated April 5, 2017. Repeat the inspection thereafter at intervals not to exceed 6,000 flight cycles or 9,000 flight hours, whichever occurs first.
If any crack is found during any inspection required by paragraph (g) of this AD, repair before further flight using a method approved in accordance with the procedures specified in paragraph (i) of this AD. Although Aviation Partners Boeing Service Bulletin AP737C-57-002, dated April 5, 2017, specifies to contact Boeing for repair instructions, and specifies that action as “RC” (Required for Compliance), this AD requires repair as specified in this paragraph.
