Is AD 58-21-01 a recurring Airworthiness Directive?

No — AD 58-21-01 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 58-21-01 apply to?

AD 58-21-01 applies to Lockheed. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 58-21-01

one-time

AD 58-21-01 · 1958-01-01 · airframe

Airworthiness Directives; accomplish the following: 1. Unless already accomplished per Lockheed wire FS/229080-W, within the next 50 flight hours thoroughly

Which aircraft AD 58-21-01 applies to

MakesLockheed

Bulkhead corrosion inspection per Lockheed wire FS/229080-W; examine aft side of bulkhead within next 50 flight hours, then recurring inspection at next block overhaul or within 4,000 flight hours (whichever occurs first); if corrosion found, unpressurized flight only pending repairs.

Whether AD 58-21-01 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 58-21-01 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.