Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Portions of DOT are affected by a lapse in appropriations. Website information may be outdated, transactions may be delayed, and inquiries may not be answered until funding is restored. Please monitor this page for updates.

Notice of proposed rulemaking (NPRM).

We propose to adopt a new airworthiness directive (AD) for all Pratt & Whitney PW4050, PW4052, PW4056, PW4056(-3), PW4156, PW4060, PW4060(- 3), PW4060A, PW4152, PW4152(-3), PW4156A, PW4158, PW4158(-3), PW4460, PW4460(-3), PW4462, and PW4462(-3) turbofan engines. This proposed AD was prompted by reports of five engine in-flight shutdowns and seven unplanned engine removals. This proposed AD would require inspections, cleaning, and engine modifications to address coking in the No. 4 bearing compartment and oil pressure and scavenge tubes. We are proposing this AD to prevent an engine fire, a fractured fan drive shaft, and damage to the airplane.

View PDF