Is AD 86-23-51 a recurring Airworthiness Directive?

No — AD 86-23-51 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 86-23-51 apply to?

AD 86-23-51 applies to Boeing Vertol — models 234. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 86-23-51

one-time

AD 86-23-51 · 1986-01-01 · airframe

Airworthiness Directives; to all persons except those persons to whom it was made immediately effective by individual telegrams issued November 14, 1986, wh

Which aircraft AD 86-23-51 applies to

MakesBoeing Vertol

Models234

Amendment 39-5659. Applies to all persons except those to whom it was made immediately effective by individual telegrams issued November 14, 1986. Applies to Model 234 series helicopters (Columbia Helicopters, Inc. operator reference in source record).

Whether AD 86-23-51 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 86-23-51 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.