Airworthiness Directives; General Electric Company (GE) GE90-110B1 and GE90-115B Turbofan Engines

摘要

We propose to adopt a new airworthiness directive (AD) for the products listed above, with certain part number (P/N) high-pressure compressor (HPC) stages 2-5 spools installed. This proposed AD would require eddy current inspection (ECI) or spot fluorescent penetrant inspection (FPI) of the stages 1-2 rotating seal teeth of the HPC stages 2-5 spool for cracks and would prohibit installation of HPC stator stage 1 interstage seals that are not pregrooved to prevent heavy rubs. This proposed AD was prompted by an aborted takeoff and two shop findings of cracks in the stages 1-2 rotating seal teeth. We are proposing this AD to detect cracks in the HPC stages 1-2 rotating seal teeth due to heavy rubs, which could result in failure of the stages 1- 2 rotating seal of the HPC stages 2-5 spool, uncontained engine failure, and damage to the airplane.