Airworthiness Directives; General Electric Company GE90-76B; GE90-77B; GE90-85B; GE90-90B; and GE90-94B Turbofan Engines

摘要

We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires initial and repetitive fluorescent penetrant inspections (FPIs) and eddy current inspections (ECIs) of the high-pressure compressor rotor (HPCR) 8-10 stage spool, part numbers (P/Ns) 1844M90G01 and 1844M90G02, for cracks between the 9-10 stages at each piece-part exposure. This AD was prompted by cracks discovered on one HPCR 8-10 spool between the 9-10 stages in the weld joint. We are issuing this AD to prevent failure of the HPCR 8-10 stage spool, uncontained engine failure, and damage to the airplane.