Airworthiness Directive · Amendment 39-15180 · Pratt & Whitney (PW) JT9D-7R4 Series Turbofan Engines
Pratt & Whitney (PW) JT9D-7R4 Series Turbofan Engines
Superseded. A later AD replaced this one: AD 2009-10-01. Comply with the one in force.
This AD applies to Pratt & Whitney (PW) JT9D-7R4G2, -7R4E1, -7R4E4, and -7R4H1 series turbofan engines. These engines are installed on, but not limited to, Boeing 747-200, -300, 767-200, and Airbus A300-600 and A310-300 series airplanes.
The FAA is adopting a new airworthiness directive (AD) for PW JT9D-7R4 series turbofan engines. This AD requires removing reduced cooling flow 2nd stage high pressure turbine (HPT) vane assemblies, part numbers (P/Ns) 797282, 796972, 800082, 800072, 803182, 803282, and 822582, installed in 2nd stage HPT vane cluster assemblies P/Ns 797592, 797372, 799872, 799782, and 822572. It also requires a visual and a fluorescent penetrant inspection (FPI) of the 2nd stage HPT air seal assembly, P/N 815097. This AD results from a report of an uncontained failure of the 2nd stage HPT air seal assembly, caused by the air seal assembly brace disengaging from the air seal, due to insufficient cooling air flow. We are issuing this AD to prevent uncontained failure of the 2nd stage HPT air seal assembly, leading to engine in-flight shutdown and damage to the airplane.
You are responsible for having the actions required by this AD performed at the next HPT module exposure after the effective date of this AD, unless the actions have already been done.
(f) At the next HPT module exposure, remove reduced cooling flow 2nd stage HPT vane assemblies part numbers (P/Ns): 797282, 796972, 800082, 800072, 803182, 803282, and 822582, installed in 2nd stage HPT vane cluster assemblies: P/Ns 797592, 797372, 799872, 799782, and 822572.
(g) For 2nd stage HPT air seals that have operated in an engine with reduced cooling flow HPT vane assemblies, at the next HPT module exposure do the following:
(1) Perform a onetime visual inspection of the 2nd stage HPT air seal assembly, P/N 815097, using instructions in JT9D-7R4 engine manual, Section 72-51-22, Inspection/Check-01, paragraphs 1.D.(1), 1.D.(4), and 1.D.(6).
(2) Perform a fluorescent penetrant inspection (FPI) of the 2nd stage HPT air seal assembly for cracks, using instructions in JT9D-7R4 engine manual, Section 71-51-00, Inspection/Check-03.
For the purpose of this AD, an HPT module exposure is defined as removing the 1st stage HPT rotor or the 2nd stage HPT rotor from the HPT case.
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.
