Applicability: Rolls-Royce plc (RR) model
RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 turbofan
Requirement: removal from service of certain
high pressure (HP) turbine discs before they reach newly
established life limits.
Background: This amendment is prompted by the
manufacturer's inspections and analysis of HP turbine discs that
have accumulated high cycles. The actions specified by this AD are
intended to prevent machining-induced cracking of the HP turbine
disc which could cause an uncontained HP turbine disc failure and
damage to the airplane.