Airworthiness Directive · Amendment 39-15824 · Pratt & Whitney (PW) JT9D-7 Series Turbofan Engines
Pratt & Whitney (PW) JT9D-7 Series Turbofan Engines
This AD applies to Pratt & Whitney (PW) JT9D-7, -7A, -7AH, -7H, -7F, and -7J turbofan engines. These engines are installed on, but not limited to, Boeing 747 series airplanes.
The FAA is adopting a new airworthiness directive (AD) for PW models JT9D-7, -7A, -7AH, -7H, -7F, and -7J turbofan engines. This AD requires initial and repetitive borescope inspections of the 2nd stage high-pressure turbine (HPT) rotor and stator assembly. This AD results from an uncontained failure of a 2nd stage HPT rotor disk that caused the engine to separate from the airplane. We are issuing this AD to prevent failure of the 2nd stage HPT rotor disk, which could result in uncontained engine failure, damage to the airplane, and the engine separating from the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
Within 100 cycles-in-service (CIS) after the effective date of this AD, or within 1,000 CIS after the last installation of the second stage HPT vanes, whichever occurs later, do the following:
(1) Use the Accomplishment Instructions of PW Alert Service Bulletin (ASB) JT9D A6488, Revision 1, dated April 18, 2008, to borescope-inspect the 2nd stage HPT rotor and stator assembly either on-wing or in the shop.
(2) If you see any damage or contact between the 2nd stage HPT vanes and the 2nd stage HPT rotor, remove the engine from service.
Thereafter, within 1,000 cycles-since-last inspection, do the following:
(1) Use the Accomplishment Instructions of PW ASB JT9D A6488 Revision 1, dated April 18, 2008, to borescope-inspect the 2nd stage HPT rotor and stator assembly either on-wing or in the shop.
(2) If you see any damage or contact between the 2nd stage HPT vanes and the 2nd stage HPT rotor, remove the engine from service.
Installing the 2nd stage HPT vanes as specified in paragraphs 1.B.(1) through 1.B.(32) of the JT9D-7 Engine Manual Revision 122, dated February 15, 2008, terminates the repetitive inspection requirement specified in paragraph (g) of this AD.
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.
