The International Air Transport Association (IATA) has warned that maintenance, repair and overhaul (MRO) bottlenecks affecting the latest generation of single-aisle aircraft engines are disrupting airline operations and could become significantly worse as global fleets continue to expand.
Produced in collaboration with consultancy Emerton, IATA’s new report examines maintenance challenges facing CFM International LEAP engines and Pratt & Whitney Geared Turbofan (GTF) engines. The study identifies engine durability issues, shortages of spare parts and engines, and limited access to the aftermarket as major factors increasing aircraft downtime and operational costs.
Grounded Aircraft and Rising Maintenance Demand
According to the report, the number of grounded aircraft powered by Pratt & Whitney GTF engines peaked at 648 in March 2025, representing approximately 28% of the global GTF fleet. Many aircraft were awaiting engine repairs, replacement engines or critical spare parts.
As a result, airlines have been forced to retain older aircraft in service, extend lease agreements, acquire additional leased aircraft and adjust flight schedules to compensate for reduced fleet availability.
The report warns that the challenge will intensify as deliveries of new-generation single-aisle aircraft continue to grow. In 2024, manufacturers delivered approximately 2,000 engines, including 1,200 LEAP engines and 800 GTF engines.
Between 2030 and 2040, annual deliveries are expected to stabilize at around 3,700 engines per year, comprising approximately 2,500 LEAP engines and 1,200 GTF engines.
Maintenance demand is projected to increase sharply during the same period. Annual shop visits for LEAP engines are forecast to rise from between 600 and 800 in 2025 to more than 5,000 by 2040, while GTF engine shop visits are expected to grow from around 1,000 to more than 2,000 annually.
IATA Calls for Industry Action
“Engine MRO bottlenecks are disrupting airline operations. Without significant changes, this will only get worse as the fleet of latest-generation single-aisle aircraft grows,” said Willie Walsh, Director General of IATA.
Walsh said manufacturers are investing in additional maintenance capacity, but warned that increasing capacity alone will not solve the problem. He called for improved access to spare parts, more approved repair options, fair competition in the aftermarket and greater availability of independent maintenance providers.
Recommendations to Improve Resilience
IATA outlined several measures to improve the resilience of the aircraft engine maintenance sector. These include accelerating the approval of repair solutions to reduce component scrappage, expanding licensed production of critical engine parts and increasing the use of serviceable components recovered from retired engines.
The association also urged manufacturers to remove barriers that limit independent MRO providers’ access to spare parts, technical information and repair tools, allowing additional maintenance capacity to enter the market.
Other recommendations include securing long-term access to spare parts through aircraft and engine purchase agreements and encouraging all aircraft and engine manufacturers to adopt transparent aftermarket policies that support customer choice and the use of regulator-approved alternative parts and repairs.
Long-Term Industry Collaboration Needed
IATA said airlines, aircraft manufacturers, engine manufacturers, lessors and maintenance providers must work together to improve spare parts availability, expand repair capabilities and better align maintenance capacity with the rapid growth of next-generation aircraft fleets.
Walsh added that improving long-term operational resilience will require a more transparent and competitive aftermarket, enabling airlines to return engines to service more quickly while supporting future fleet expansion with adequate maintenance capacity.
