Airworthiness Directive 2026-09-12
recurringAirworthiness Directives; The Boeing Company Airplanes
What this AD requires
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by a report of cracks found in the fuselage skin underneath the aft drain mast. This AD requires repetitive inspections of the fuselage skin and structure common to the aft drain mast for any crack or corrosion and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.
Which aircraft AD 2026-09-12 applies to
Applicability limited to airplanes identified in Boeing Alert Service Bulletin 737-53A1409, Revision 1, dated October 27, 2023.
Whether AD 2026-09-12 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.