Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede airworthiness directive (AD) 2016-13- 05, which applies to all General Electric Company (GE) GE90-76B, GE90- 77B, GE90-85B, GE90-90B, and GE90-94B turbofan engines. AD 2016-13-05 requires eddy current inspection (ECI) of the high-pressure compressor (HPC) stage 8-10 spool at each shop visit for all affected engines and ECI or ultrasonic inspection (USI) for certain affected engines. Since we issued AD 2016-13-05, we determined that the risk of the failure of an HPC stage 8-10 spool was excessive without repetitive USI prior to shop visit. This proposed AD would require initial and repetitive on- wing USIs of the HPC stage 8-10 spool for certain engines prior to shop visit and ECI of all affected engines at each shop visit. We are proposing this AD to correct the unsafe condition on these products.