Airworthiness Directives; General Electric Company CF6 Series Turbofan Engines

摘要

This amendment supersedes an existing airworthiness directive (AD), applicable to General Electric Company (GE) CF6 series turbofan engines, that currently requires initial and repetitive ultrasonic and eddy current inspections of high pressure compressor rotor (HPCR) stage 3-9 spools for cracks. This amendment defines more aggressive inspection intervals for certain HPCR stage 3-9 spools, adds CF6-80E1 engines to the inspection program, adds inspection requirements for spools manufactured from 8 inch diameter billet, adds inspection requirements for stage 3-5 blade slot bottoms, and adds inspection requirements for web and hub-to-web transition areas. This amendment is prompted by analysis of recent HPCR stage 3-9 spool inspection results and separations, and assessment of the adequacy of the existing program to prevent HPCR stage 3-9 spool cracking and separation. As a result of that assessment, the FAA has determined there is a need to make changes to the existing AD. The actions specified by this AD are intended to prevent HPCR stage 3-9 spool cracking and separation, which can result in an uncontained engine failure and aircraft damage.