Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Textron Lycoming ALF502L series turbofan engines. This proposal would establish reduced retirement life limits for stage 1 and stage 3-7 compressor disks, and stage 2 turbine disks, and provide a drawdown schedule for disks already beyond the reduced retirement life limits. This proposal is prompted by new life analyses of these components. The actions specified by the proposed AD are intended to prevent disk failure, which could result in an inflight engine shutdown and extensive engine damage.