AD 2015-21-04
Effective 11/27/2015 · Published 10/23/2015
Airworthiness Directives; Pratt & Whitney Turbofan Engines
Summary
We are adopting a new airworthiness directive (AD) for certain Pratt & Whitney (PW) PW4164, PW4168, PW4168A, PW4164-1D, PW4168-1D, PW4168A-1D, and PW4170 turbofan engines. This AD was prompted by crack finds in the 6th stage low-pressure turbine (LPT) disk. This AD requires removal of the affected 6th stage LPT disks. We are issuing this AD to prevent failure of the 6th stage LPT disk, which could lead to an unconta…