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Airworthiness Directive 99-11-09

recurring
Official AD 99-11-09 · FR doc 99-13322 · 1999-05-26 · turbine engine

Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines

What this AD requires

This document supersedes an existing airworthiness directive (AD), applicable to Pratt & Whitney (PW) JT9D series turbofan engines, that currently requires initial and repetitive in-shop or on-wing inspections of the diffuser case rear rail for cracking, and removal, if necessary, of the diffuser case. This AD will reduce the allowable crack length, reduce the inspection intervals, and introduce an improved inspection method. This AD is prompted by continued reports of diffuser case ruptures, and improved understanding of crack propagation rates. The actions specified by this AD are intended to prevent diffuser case rupture, uncontained engine failure, and 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 99-11-09 applies to

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

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

Whether AD 99-11-09 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 99-11-09 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.