Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Pratt & Whitney (PW) JT3D series turbofan engines. This proposal would require inspection of steel high pressure compressor (HPC) disks for corrosion, recoating or replating those disks, or replacing those disks as necessary. This proposal is prompted by reports of a failure of a PW JT8D steel HPC disk, which is similar in design to the PW JT3D steel HPC disks. The actions specified by the proposed AD are intended to prevent steel HPC disk failure due to corrosion, which could result in an uncontained engine failure and damage to the aircraft.