Is AD 2001-12-23 a recurring Airworthiness Directive?

No — AD 2001-12-23 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 2001-12-23 apply to?

AD 2001-12-23 applies to Boeing — models 747. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 2001-12-23

one-time

Official AD 2001-12-23 · FR doc 01-15572 · 2001-06-22 · airframe

Airworthiness Directives; Boeing Model 747-100, 747-200, 747-300, 747SP, and 747SR Series Airplanes Powered by Pratt & Whitney JT9D-3 and JT9D-7 Series Engines

What this AD requires

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 747-100, 747-200, 747-300, 747SP, and 747SR series airplanes powered by Pratt & Whitney JT9D-3 or JT9D-7 series engines, that currently requires inspections of the vertical chords of the aft torque bulkhead of the outboard nacelle struts, and corrective action, if necessary. That AD also gives an optional modification of the vertical chords, which ends the inspections. This amendment requires the previously optional modification. The actions specified by this AD are intended to prevent cracking of the vertical chords adjacent to the lower spar fitting, which could result in separation of the diagonal brace load path. Continued operation with a separated diagonal brace load path increases loads on the upper link, midspar fitting, and dual side links, which could result in separation of the strut and engine from the airplane.

Which aircraft AD 2001-12-23 applies to

MakesBoeing

Models747

Restatement of AD 2000-23-25; visual, eddy current, and ultrasonic inspection of the vertical chords of the aft torque bulkhead of the outboard nacelle struts per Boeing Alert SB 747-54A2201, dated Sept 28, 2000, to prevent strut/engine separation from cracking.

Whether AD 2001-12-23 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 2001-12-23 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.