TailplateTailplate
Run a report

Airworthiness Directive 99-14-08

recurring
Official AD 99-14-08 · FR doc 99-17427 · 1999-07-13 · turbine engine

Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

What this AD requires

This amendment supersedes an existing airworthiness directive (AD), applicable to Pratt & Whitney (PW) JT9D series turbofan engines, that currently requires initial and repetitive inspections of the sixth stage low pressure turbine (LPT) inner airseal, and modification of the sixth stage LPT inner airseal to reduce the potential for two failure modes. This amendment requires additional repetitive borescope inspections for sixth stage LPT inner airseals found with cracks less than one inch in length. This amendment is prompted by the publication of a revision to a PW service bulletin that introduces the new borescope inspections. The actions specified by this AD are intended to prevent an uncontained failure of the sixth stage LPT inner airseal, which can result in damage to the aircraft.

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

Which aircraft AD 99-14-08 applies to

MakesPratt & Whitney
ModelsJT9D-59A, JT9D-70A, JT9D-7Q, JT9D-7Q3, JT9D

Installed on but not limited to Boeing 747 series, McDonnell Douglas DC-10 series, and Airbus A300 series aircraft.

Whether AD 99-14-08 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 99-14-08 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.