Airworthiness Directives; CFM International S.A. Model CFM56 Turbofan Engines

The FAA is adopting a new airworthiness directive (AD) for CFM International S.A. CFM56-2, CFM56-3, CFM56-5A, CFM56-5B, CFM56-5C, and CFM56-7B series turbofan engines with certain part number (P/N) and serial number (SN) high-pressure compressor (HPC) 4-9 spools installed. This AD requires removing certain HPC 4-9 spools listed by P/N and SN in this AD. This AD results from reports of certain HPC 4-9 spools that Propulsion Technology LLC (PTLLC) improperly repaired and returned to service. We are issuing this AD to prevent cracking of the HPC 4-9 spool, which could result in possible uncontained failure of the spool and damage to the airplane.