Is AD 97-31021 a recurring Airworthiness Directive?

No — AD 97-31021 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 97-31021 apply to?

AD 97-31021 applies to Fokker — models 0100. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 97-31021

one-time

AD 97-31021 · 1997-11-28 · airframe

Airworthiness Directives; Fokker Model F28 Mark 0070 and 0100 Series Airplanes

What this AD requires

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0070 and 0100 series airplanes, that requires a one-time operational test of a certain pitot heating system, repair or replacement of failed elements, and repair or replacement of the pitot heating system with a new improved system. This amendment also requires installation of new power supply wiring with increased gauge thickness, and a circuit breaker with an increased amperage rating. This amendment is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent icing of the No. 1 pitot tube, which could result in failure of the No. 1 Air Data Computer, or output of erroneous airspeed data to all on-side subsidiary systems, including the Automatic Flight Control and Augmentation System.

Which aircraft AD 97-31021 applies to

MakesFokker

Models0100

certain

Whether AD 97-31021 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 97-31021 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.