Is AD 51-02-01 a recurring Airworthiness Directive?

No — AD 51-02-01 is a one-time directive. Verify it was complied with in the aircraft's records.

Airworthiness Directive 51-02-01

Q: Which aircraft does AD 51-02-01 apply to?

AD 51-02-01 applies to Metropolitan Airparts — models Model A Airstair Door, Model C Airstair Door, Model D Airstair Door. Serial/part conditions may narrow it to specific aircraft.

one-time

AD 51-02-01 · 1951-01-01 · appliance

Airworthiness Directives; will be considered to meet this objective. (3) Compliance required by January 1, 1953. To reduce the possibility of inadvertent op

Which aircraft AD 51-02-01 applies to

MakesMetropolitan Airparts

ModelsModel A Airstair Door, Model C Airstair Door, Model D Airstair Door

Install stops to positively limit lock mechanism travel, to reduce the possibility of inadvertent opening of the door in flight, per Metropolitan Airparts Service Bulletins No. MAP-4A, MAP-5A, or MAP-6A (for Model A, C, or D Airstair Doors respectively); compliance required by January 1, 1953.

Whether AD 51-02-01 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 51-02-01 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 →

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.