Airworthiness Directive 99-04-05
one-timeAirworthiness Directives; Pratt & Whitney JT9D Series Turbofan Engines
What this AD requires
This amendment adopts a new airworthiness directive (AD), applicable to certain Pratt & Whitney (PW) JT9D series turbofan engines, that requires a fluorescent penetrant inspection (FPI) of the rear skirt of the diffuser case for cracks, and, if necessary, blending down to minimum wall thickness to remove cracks and subsequent FPI to determine if cracks have been removed, polishing, and shotpeening. If the cracks are shown by subsequent FPI not to have been removed, this AD requires removing the diffuser case from service and replace with a serviceable part. This amendment is prompted by a report of a diffuser case rupture during takeoff roll that resulted in damage to the aircraft. The actions specified by this AD are intended to prevent diffuser case rupture due to cracks, which can result in an uncontained engine failure and damage to the aircraft.
Which aircraft AD 99-04-05 applies to
Applies only to engines with diffuser cases P/Ns 772173, 772173-001, 772173-002, 782222, 782222-001, and 782222-002 installed. Installed on but not limited to Boeing 747 series, McDonnell Douglas DC-10 series, and Airbus A300 series aircraft.
Whether AD 99-04-05 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:
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.