Airworthiness Directive · Amendment 39-11029 · Pratt & Whitney JT9D Series Turbofan Engines
Pratt & Whitney JT9D Series Turbofan Engines
Pratt & Whitney (PW) Model JT9D-7Q, -7Q3, -59A, and -70A turbofan engines, with diffuser cases, part numbers (P/Ns) 772173, 772173-001, 772173-002, 782222, 782222-001, and 782222-002, installed. These engines are installed on but not limited to Boeing 747 series, McDonnell Douglas DC-10 series, and Airbus A300 series aircraft.
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.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
