Airworthiness Directives; Rolls-Royce plc RB211-524H-36 Series Turbofan Engines

This amendment adopts a new airworthiness directive (AD) that is applicable to Rolls-Royce plc RB211-524H-36 series turbofan engines. This action requires, prior to further flight, installing an improved combustion liner with a strengthened head and improved heat shields. This amendment is prompted by a report of burn through of a combustor case that led to burning away of the thrust reverser and translating cowl and subsequent fire damage to the engine pylon. The actions specified in this AD are intended to prevent burn through of the combustor case due to combustion liner cracking, which can result in an engine fire and damage to the aircraft.