Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Rolls-Royce (RR) Corporation (formerly Allison Engine Company) AE 3007A and AE 3007C model engines with high pressure turbine (HPT) 1st to 2nd stage turbine spacer part number (P/N) 23058369 installed. This proposal would require removal and replacement of the HPT 1st to 2nd stage turbine spacer P/N 23058369 before it reaches its new reduced engine cycle life limit. This proposal is prompted by the results of a detailed component analysis that indicates that the HPT 1st to 2nd stage turbine spacer stresses are higher than predicted. The actions specified by the proposed AD are intended to prevent HPT 1st to 2nd stage turbine spacer failure which could result in an uncontained engine failure and damage to the airplane.