AD FAA-2016-6744

We are adopting a new airworthiness directive (AD) for certain Rolls-Royce plc (RR) RB211-Trent 875-17, RB211-Trent 877-17, RB211- Trent 884-17, RB211-Trent 884B-17, RB211-Trent 892-17, RB211-Trent 892B-17, and RB211-Trent 895-17 turbofan engines. This AD requires machining and inspecting parts related to the high-pressure compressor (HPC) and replacing HPC parts found defective. This AD was prompted by inspection of RR Trent 800 engines returned from service that revealed flame erosion and axial cracking on the stage 3 disk rim of the HPC stage 1-4 rotor disks shaft. We are issuing this AD to correct the unsafe condition on these products.