Is AD 2020-21-17 a recurring Airworthiness Directive?

Yes — AD 2020-21-17 requires a repetitive inspection. Next-due depends on the aircraft's time in service.

Which aircraft does AD 2020-21-17 apply to?

AD 2020-21-17 applies to Boeing — models 757-200, 757-200PF, 757-200CB, 757-300, 757. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2020-21-17

recurring

Official AD 2020-21-17 · FR doc 2020-27007 · 2020-12-10 · airframe

Airworthiness Directives; The Boeing Company Airplanes

What this AD requires

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.

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 2020-21-17 applies to

MakesBoeing

Models757-200, 757-200PF, 757-200CB, 757-300, 757

Installation of STC ST01518SE does not exempt affected airplanes from this AD; a change-in-product-model alternative method of compliance applies to those aircraft.

Whether AD 2020-21-17 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 2020-21-17 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.