Summary
The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to Pratt & Whitney JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR turbofan engines. This proposal would require removal from service of certain part number (P/N) 3rd-4th and 4th-5th stage compressor rotor spacer assemblies and incorporation of a new tierod retention configuration. This proposal is prompted by two reports of uncontained failure of JT8D turbofan engines, caused by turbine rotor overspeed resulting from first and second stage fan section separation from the low pressure compressor (LPC). The actions specified by the proposed AD are intended to prevent first and second stage fan section separation from the LPC, resulting in turbine rotor overspeed, uncontained engine failure, and damage to the airplane.