Is AD 98-09-23 a recurring Airworthiness Directive?

No — AD 98-09-23 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 98-09-23 apply to?

AD 98-09-23 applies to Lockheed. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 98-09-23

one-time

Official AD 98-09-23 · FR doc 98-11088 · 1998-04-29 · airframe

Airworthiness Directives; Lockheed Model L-1011 Series Airplanes Equipped With Rolls Royce Model RB211-22B Engines

What this AD requires

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Lockheed Model L-1011 series airplanes, that currently requires various modifications and corrective actions to prevent a potential fire hazard caused by heat damage to the flex fuel feed line from an undetected gearbox fire. In lieu of the various modifications and corrective actions, that AD also provides for an optional terminating action (i.e., installation of a vent air tube in the gear compartment and thickened gearbox housings) for another existing AD. For airplanes on which that optional terminating action has been accomplished, this amendment requires accomplishment of the various modifications and corrective actions. This amendment is prompted by a report indicating that, due to bearing failure, an in- flight fire occurred on an airplane on which a thickened gearbox housing was installed. The actions specified by this AD are intended to detect and correct bearing failure, which could lead to a fire in the gearbox.

Which aircraft AD 98-09-23 applies to

MakesLockheed

Applies to airplanes identified in a preceding applicability provision not captured in this excerpt (referenced only as 'each airplane identified in the preceding applicability provision'). Addresses bearing failure that could lead to a fire in the gearbox; requires accomplishment of Lockheed Service Bulletin 093-26-036 (fire detector segment) and 093-71-067 (gearbox breather duct modification), and Rolls-Royce Service Bulletin RB.211-72-4666 (vent air tube) and RB.211-72-8138 (additional No. 7 fire sensor); constitutes terminating action for AD 85-09-03.

Whether AD 98-09-23 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 98-09-23 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.