Summary
This action withdraws a notice of proposed rulemaking (NPRM). That NPRM proposed a new airworthiness directive (AD) that applies to certain RRD Tay 650-15 series turbofan engines. That proposed action would have required initial and repetitive inspections of the high pressure compressor (HPC) shaft and high pressure turbine (HPT) shaft for spline flank wear. Since we issued that NPRM, the Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, notified us that the spline flank wear inspections are now downgraded by RRD from "mandatory'' to "recommended''. Accordingly, we withdraw the proposed rule.