Summary
This document proposes to adopt a new airworthiness directive (AD) that is applicable to Honeywell International, Inc. (formerly AlliedSignal Inc. and Textron Lycoming) ALF502 and LF507 series turbofan engines. This proposal would require removing from service certain gas producer turbine (GPT) components prior to reaching new, lower cyclic life limits using drawdown plans, and replacing with serviceable parts. This proposal is prompted by continuous analysis of field-returned hardware indicating smaller service life margins than originally expected. The actions specified by the proposed AD are intended to prevent GPT component failure, which could result in an uncontained engine failure and damage to the airplane.