Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Pratt & Whitney Division (PW) PW4164, PW4164-1D, PW4168, PW4168-1D, PW4168A, PW4168A-1D, and PW4170 model turbofan engines with a certain outer combustion chamber assembly and 3rd stage low-pressure turbine (LPT) duct segments installed. This proposed AD was prompted by reports of damaged or failed 3rd stage LPT duct segments on PW engines with the Talon IIB outer combustion chamber assembly configuration installed. This proposed AD would require removing and replacing certain 3rd stage LPT duct segments. The FAA is proposing this AD to address the unsafe condition on these products.