Is AD 01-13737 a recurring Airworthiness Directive?

No — AD 01-13737 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 01-13737 apply to?

AD 01-13737 applies to Air Tractor, Inc. At-400, At-500, And At-800 — models AT-400, AT-500, AT-800. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 01-13737

one-time

AD 01-13737 · 2001-06-04 · airframe

Airworthiness Directives; Air Tractor, Inc. AT-400, AT-500, and AT-800 Series Airplanes

What this AD requires

This amendment revises AD 2001-10-04, which concerns certain Air Tractor, Inc. (Air Tractor) AT-400, AT-500, and AT-800 series airplanes. AD 2001-10-04 superseded AD 2000-14-51 and lowers the safe life for the wing lower spar cap on these airplanes. The AD was the result of numerous reports of cracks in the 3/8-inch bolthole of the wing lower spar cap on the affected airplanes. We inadvertently included certain AT-800 series airplanes in the Applicability of this AD. Those AT-800 series airplanes that are equipped with the factory- supplied part number 80540 computerized fire gate should not be affected by AD 2001-10-04. This action revises the AD to reflect this change and to provide information for applying for an alternative method of compliance with this AD. The actions specified by this AD are intended to prevent fatigue cracks from occurring in the wing lower spar cap before the originally established safe life is reached. Fatigue cracks in the wing lower spar cap, if not detected and corrected, could result in the wing separating from the airplane during flight.

Which aircraft AD 01-13737 applies to

MakesAir Tractor, Inc. At-400, At-500, And At-800

ModelsAT-400, AT-500, AT-800

Part-conditional — 80540.

certain

Whether AD 01-13737 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 01-13737 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.