Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan Engines
The FAA is revising an existing airworthiness directive (AD) for Rolls-Royce plc (RR) RB211-22B series, RB211-524B, -524C2, -524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines with high pressure compressor (HPC) stage 3 disc assemblies, part numbers (P/Ns) LK46210, LK58278, LK67634, LK76036, UL11706, UL15358, UL22577, UL22578, and UL24738 installed. That AD currently requires removing from service certain disc assemblies before they reach their full published life if not modified with anticorrosion protection. This AD requires the same actions but relaxes the removal compliance time for certain disc assemblies that have a record of detailed inspection. This AD results from the FAA allowing certain affected disc assemblies that have a record of a detailed inspection, to remain in service for a longer period than the previous AD allowed. We are issuing this AD to relax the compliance time for disc assemblies manufactured both "before and after 1990" by providing an option to track the disc life based on a record of a detailed inspection rather than by its entry into service date, while continuing to prevent corrosion-induced uncontained disc assembly failure, resulting in damage to the airplane.