Airworthiness Directive · Amendment 39-12144 · Pratt & Whitney PW4000 Series Turbofan Engines
Pratt & Whitney PW4000 Series Turbofan Engines
This airworthiness directive is applicable to Pratt & Whitney (PW) PW4052, PW4056, PW4060, PW4060A, PW4062, PW4152, PW4156, PW4156A, PW4158, PW4164, PW4168, PW4168A, PW4460, and PW4462 turbofan engines, with low pressure turbine (LPT) 4th stage air seal, part number (P/N) 50N478 or P/N 50N478-001 installed. These engines are installed on but not limited to Boeing 747, 767, McDonnell Douglas MD-11, Airbus Industrie A300, A310, and A330 series airplanes. Note 1. This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment supersedes airworthiness directive (AD) 2000- 25-06, dated December 5, 2000, that is applicable to certain Pratt & Whitney (PW) PW4000 turbofan engines with the current design low pressure turbine (LPT) 4th stage air seal installed. That AD currently requires, based on engine model, replacement of the current design seal with a new design seal, or with a modified seal. This amendment adds the listing of certain engine serial numbers, to correct an error in the applicability section of AD 2000-25-06, for engines affected by PW Service Bulletin (SB) PW4 ENG 72-657, Revision 1, dated July, 19, 2000. This correction is prompted by comments received on AD 2000-25-06. The actions specified by this AD are intended to reduce stresses that could lead to LPT 4th stage air seal cracking, resulting in seal fracture, 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.
