Is AD 2021-12-04 a recurring Airworthiness Directive?

No — AD 2021-12-04 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2021-12-04 apply to?

AD 2021-12-04 applies to Fokker Services B.V. — models F28 Mark 0070, F28 Mark 0100, F28. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2021-12-04

one-time

Official AD 2021-12-04 · FR doc 2021-13108 · 2021-06-24 · airframe

Airworthiness Directives; Fokker Services B.V. Airplanes

What this AD requires

The FAA is adopting a new airworthiness directive (AD) for all Fokker Services B.V. Model F28 Mark 0070 and 0100 airplanes. This AD was prompted by a report that corrosion was found on the horizontal flange on the front spar lower boom, between the rebate strap and the lower boom, and resulted in bulging. This AD requires doing a detailed visual inspection to detect any bulging, loose, and missing countersunk fastener heads at the left-(LH) and right-hand (RH) outer wing lower skin of the front spar between certain wing stations, and applicable on-condition actions, as specified in a European Union Aviation Safety Agency (EASA), which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.

Which aircraft AD 2021-12-04 applies to

MakesFokker Services B.V.

ModelsF28 Mark 0070, F28 Mark 0100, F28

Whether AD 2021-12-04 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 2021-12-04 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.