Is AD 2021-10-11 a recurring Airworthiness Directive?

Yes — AD 2021-10-11 requires a repetitive inspection. Next-due depends on the aircraft's time in service.

Which aircraft does AD 2021-10-11 apply to?

AD 2021-10-11 applies to The Boeing Company — models 737-100, 737-200, 737-200C, 737-300, 737-400, 737-500, 737. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2021-10-11

recurring

Official AD 2021-10-11 · FR doc 2021-13122 · 2021-06-24 · airframe

Airworthiness Directives; The Boeing Company Airplanes

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by a report indicating that a crack was found on the splice angle flange that is attached to the station (STA) 540 bulkhead in the area between certain stringers. This AD requires repetitive surface high frequency eddy current (HFEC) inspections at the radius of the left- and right-side of the STA 540 bulkhead splice angle for any cracking, and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.

Repetitive inspection. Re-inspect. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 2021-10-11 applies to

MakesThe Boeing Company

Models737-100, 737-200, 737-200C, 737-300, 737-400, 737-500, 737

Part-conditional — ST01219SE.

Installation of Supplemental Type Certificate (STC) ST01219SE does not affect the ability to accomplish the actions required by this AD; a 'change in product' alternative method of compliance provision applies for airplanes with that STC installed.

Whether AD 2021-10-11 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:

Method of compliance — The specific action taken (inspected, replaced, modified) and to what revision.

Date — When the work was done.

Aircraft time — Total time in service / tach at compliance — how recurring next-due is computed.

Signature & certificate — The A&P/IA who returned it to service, with certificate number.

Is AD 2021-10-11 complied with on your aircraft?

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.