Is AD 99-11-12 a recurring Airworthiness Directive?

Yes — AD 99-11-12 requires a repetitive inspection every 5000 hours. Next-due depends on the aircraft's time in service.

Which aircraft does AD 99-11-12 apply to?

AD 99-11-12 applies to Boeing — models 747. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 99-11-12

recurring

Official AD 99-11-12 · FR doc 99-13483 · 1999-05-28 · airframe

Airworthiness Directives; Boeing Model 747-400 Series Airplanes Powered by Pratt & Whitney PW4000 Engines

What this AD requires

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-400 series airplanes, that requires repetitive inspections to ensure proper installation of the engine thrust link components, and follow-on corrective action, if necessary; and replacement of the forward engine mount end cap assembly with an improved end cap assembly. Such replacement, when accomplished, will terminate the repetitive inspections. This amendment is prompted by a report of fatigue cracking of end cap bolts, caused by improper installation. Subsequent investigation revealed that properly installed end caps also are subject to early fatigue cracking. The actions specified by this AD are intended to prevent failure of the end cap assembly, which could lead to separation of the engine from the airplane in the event of a primary thrust linkage failure.

Repetitive inspection. Re-inspect every 5000 hours. The next-due date/hours depend on this aircraft’s time in service — a records report computes it from the logbooks.

Which aircraft AD 99-11-12 applies to

MakesBoeing

Models747

Part-conditional — 310T3026-1.

Concerns the forward engine mount end cap assembly/thrust link components to prevent possible engine separation; Group 1 and Group 2 airplanes (as identified in Boeing Alert Service Bulletin 747-71A2283, dated October 10, 1996) have different compliance actions; as of the effective date, no person may install a forward engine mount end cap having part number 310T3026-1.

Whether AD 99-11-12 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 99-11-12 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.