Summary
We propose to adopt a new airworthiness directive (AD) for certain Rolls-Royce plc (RR) RB211 Trent 875-17, 877-17, 884-17, 884B- 17, 892-17, 892B-17, and 895-17 turbofan engines. The proposed AD was prompted by thin-walled low pressure (LP) turbine bearing support and exhaust case assemblies having been delivered into service. This proposed AD would require inspection of the affected LP turbine bearing support and exhaust case assembly and, if necessary, its replacement with a part eligible for installation. We are proposing this AD to prevent failure of the LP turbine bearing support and exhaust case assembly, which could lead to engine separation and damage to the airplane.