Airworthiness Directive · Amendment 39-17179 · Pratt & Whitney Division Turbofan Engines
Pratt & Whitney Division Turbofan Engines
This AD applies to the following Pratt & Whitney Division turbofan engines:
(1) PW4000-94″ engine models PW4050, PW4052, PW4056, PW4152, PW4156, PW4650, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4156A, PW4158, PW4160, PW4460, and PW4462, including models with any dash-number suffix, with a 1st stage high-pressure turbine (HPT) seal support, part number (P/N) 55K601 (contained within assembly P/N 55K602-01) or P/N 50K532 (contained within assembly P/N 50K530-01), installed.
(2) PW4000-100″ engine models PW4164, PW4164C, PW4164C/B, PW4168, and PW4168A with a 1st stage HPT seal support, P/N 55K601 (contained within assembly P/N 55K602-01) or P/N 50K532 (contained within assembly P/N 50K530-01), installed.
We are adopting a new airworthiness directive (AD) for certain Pratt & Whitney Division PW4000-94" and PW4000-100" turbofan engines having a 1st stage high-pressure turbine (HPT) seal support, part number (P/N) 55K601 (contained within assembly P/N 55K602-01) or P/N 50K532 (contained within assembly P/N 50K530-01), installed. This AD was prompted by 58 reports of cracked 1st stage HPT air seal rings, including 15 in-flight engine shutdowns. This AD requires removal and replacement of the 1st stage HPT seal support and inspection of the 1st stage HPT air seal ring. We are issuing this AD to prevent failure of the 1st stage HPT air seal ring, which could lead to an internal oil fire, uncontained engine failure, and damage to the airplane.
Comply with this AD the next time the HPT module is removed from the engine, unless already done.
(1) Remove the 1st stage HPT seal support, P/N 55K601 (contained within assembly P/N 55K602-01) or P/N 50K532 (contained within assembly P/N 50K530-01), from service and replace it with a serviceable 1st stage HPT seal support.
(2) Remove the 1st stage HPT air seal ring, P/N 50L664, from the engine and fluorescent-penetrant-inspect, or eddy current-inspect, it for cracks. If found cracked, remove the 1st stage HPT air seal ring from service.
For the purpose of this AD, a serviceable 1st stage HPT seal support is one that has a P/N that is not listed in 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.
