Airworthiness Directives; Pratt & Whitney JT9D-3A, -7, -7A, -7AH, -7H, -7F, -7J, -20, and -20J Turbofan Engines

The FAA is adopting a new airworthiness directive (AD) for Pratt & Whitney (PW) JT9D-3A, -7, -7A, -7AH, -7H, -7F, -7J, -20, and - 20J turbofan engines. This AD clarifies a life limit for certain part numbers of 6th stage low pressure turbine (LPT) air seals, and requires their removal from service before accumulating 15,000 cycles-since-new (CSN). This AD results from reports of certain 6th stage LPT air seals possibly not being life tracked due to confusion from updates to the engine manuals. We are issuing this AD to prevent failure of the 6th stage LPT air seal, which could cause LPT damage resulting in an uncontained engine failure.