Airworthiness Directive · Amendment 39-12753 · Pratt & Whitney JT9D-59A, -70A, -7Q, and -7Q3 Turbofan Engines
Pratt & Whitney JT9D-59A, -70A, -7Q, and -7Q3 Turbofan Engines
Superseded. A later AD replaced this one: AD 2005-05-13. Comply with the one in force.
This airworthiness directive (AD) is applicable to Pratt & Whitney (PW) JT9D-59A, -70A, -7Q, and -7Q3 turbofan engines. These engines are installed on, but not limited to, Airbus Indusrie A300 series, Boeing 747 series, and McDonnell Douglas DC-10 series airplanes.
This amendment adopts a new airworthiness directive (AD), that is applicable to Pratt & Whitney (PW) JT9D-59A, -70A, -7Q, and -7Q3 turbofan engines. This amendment requires fluorescent penetrant inspection of the high pressure turbine (HPT) second stage airseal knife edges for cracks, each time the airseal is accessible. This amendment is prompted by reports of cracks found in the knife edges of HPT second stage airseals during HPT disassembly. The actions specified by this AD are intended to prevent failure of HPT second stage airseals due to cracks in the knife edges, which if not detected could result in uncontained engine failure and damage to the airplane.
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.
