New LEAP-1A Check Parameters Stress MRO Tracking Systems

Credit: Airbus - Stefan Kruijer

A new inspection requirement affecting CFM LEAP-1A operations in the Middle East and North Africa (MENA) is shaping up to be a maintenance record-keeping headache for some affected airlines.

The inspections, mandated in a Jan. 19 European Union Aviation Safety Agency (EASA) airworthiness directive (AD), target cracking on LEAP-1A high pressure turbine (HPT) rotor stage 1 blades. The mandate requires Airbus A320neo-family operators with CFM engines to start a recurrent inspection program after engines have accumulated 800 departures from airports in the MENA region.

"Occurrences of cracking of affected parts have been reported on engines operated extensively in the MENA region,” the AD said. "This condition, if not detected and corrected, could lead to failure of the affected parts.”

While the directive does not provide details on the issue, it appears linked to dust and other environmental variables prevalent in the MENA region. CFM advised operators to implement the program in a December service bulletin. CFM's original instructions targeted engines that flew at least 50% of their departures from MENA airports. But the parameter was changed to 800 total departures. EASA’s mandate is based on CFM’s recommendations.

Several operators expressed concern at the requirement to track MENA-specific operations, instead of a more common metric such as total hours or cycles, is burdensome.

"It is very difficult to control how many [departures] have been performed from MENA region airports and to individualize those on an engine-by-engine basis in our airworthiness control system,” Iberia told EASA in comments on a draft of the directive.

"Our approved system is not able to count the departures from a list of counties, so it can only be done manually but it cannot be done in real time,” added Cathay Pacific.

Both airlines suggested more basic thresholds be set to ensure appropriate inspections were being done without having to tally up subsets of operations. Iberia said its 12,361 LEAP-1A mainline and Iberia Express departures in 2021 included just 74, or less than 1%, from the MENA region.

“Due to the criteria...we would need to be constantly monitoring, on an engine-by-engine basis, the different take-offs each engine has and will have in the future,” the Spanish carrier added.

EASA said the MENA-specific metric is necessary.

"Available data confirm that all engines having achieved 800 departures from MENA region have to be inspected, irrespective of the percentage of departures from MENA region vs total departures,” the regulator said. It also pointed to CFM’s service bulletin for the list of specific airports covered by the program.

Intervals for follow-up inspections vary based on engine thrust rating. Those with ratings below 29,000 lb. must be re-inspected every 300 cycles, regardless of where they occurred, while higher-rated engines must be re-checked every 150 cycles.

While the EASA mandate covers only European operators, the directive is likely to be adopted by other regulators, including those that oversee airlines in the MENA region. Aviation Week Fleet Discovery shows about 80 CFM-powered A320neo family aircraft in the region out of 1,100 worldwide.

The issue also may show up on 737 MAXs powered by LEAP-1Bs, which have a similar HPT blade design as the -1A. The 737 MAX’s grounding from March 2019-December 2020 means the aircraft have not accumulated hours and cycles as quickly as their Airbus counterparts.

CFM said it is working to understand the root cause of the LEAP-1A issue. It declined to comment further.

Sean Broderick

Senior Air Transport & Safety Editor Sean Broderick covers aviation safety, MRO, and the airline business from Aviation Week Network's Washington, D.C. office.