Is AD 98-21654 a recurring Airworthiness Directive?

Yes — AD 98-21654 requires a repetitive inspection. Next-due depends on the aircraft's time in service.

Which aircraft does AD 98-21654 apply to?

AD 98-21654 applies to Fokker — models 2000, 3000, 4000. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 98-21654

recurring

AD 98-21654 · 1998-08-14 · airframe

Airworthiness Directives; Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 Series Airplanes

What this AD requires

This amendment adopts a new airworthiness directive (AD), applicable to all Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 series airplanes, that requires repetitive inspections to detect any discrepancy in the sealwire of the fireguards of the engine fire shut- off system, and repair, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent inadvertent closure of the fire shut-off valves due to ineffective or absent sealwires, which could result in in-flight engine shutdown.

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 98-21654 applies to

MakesFokker

Models2000, 3000, 4000

applicability derived from the AD summary — confirm the model/serial from the records

Whether AD 98-21654 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 98-21654 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.