EASA SIB 2012-17
CFM International CFM56-5B engines — High Cycle Fatigue Failure of Low Pressure Turbine Active Clearance Control Fuel Manifolds
Summary
EASA Safety Information Bulletin 2012-17 is an advisory document addressing high cycle fatigue failure of Low Pressure Turbine Active Clearance Control (LPTACC) fuel manifolds on CFM International CFM56-5B turbofan engines. These engines are installed on Airbus A318, A319, A320, and A321 aircraft. The bulletin aligns with FAA Special Airworthiness Information Bulletin NE-12-29 and informs European operators and maintenance organizations about the issue and recommended actions.
What Changed
This bulletin highlights the occurrence of high cycle fatigue failures in LPTACC fuel manifolds caused by unbalanced loading from foreign object damage or bird ingestion. It introduces the FAA's recommendation to replace the original fuel manifold part number 336-401-402-0 with a more robust design, part number 336-401-403-0, as detailed in CFM56-5B Service Bulletin 72-0696, revision 1. The bulletin does not mandate action but strongly advises prioritizing this replacement to reduce the risk of fuel leaks and potential engine fires.
Why It Matters
The fatigue failure of LPTACC fuel manifolds can lead to fuel leaks within engine fire zones, posing a safety risk to aircraft operation. For operators and maintenance organizations, addressing this issue proactively minimizes the chance of engine fire incidents and ensures continued airworthiness. Compliance teams benefit from awareness of the recommended service bulletin to maintain regulatory alignment and operational safety.
What To Do
Operators and maintenance facilities should plan to replace the original LPTACC fuel manifold (part number 336-401-402-0) with the improved design (part number 336-401-403-0) following CFM56-5B Service Bulletin 72-0696, revision 1. This replacement should be completed at the earliest convenience and no later than the end of 2015. Although not mandatory, prioritizing this modification is advised to mitigate risk.