Aircraft engine maintenance strain threatens to slow aviation growth

A new IATA and Emerton study says engine MRO capacity, spare parts and repair access are already constraining operations, with 648 GTF-powered aircraft grounded at the 2025 peak Maintenance demand is set to rise sharply as LEAP and GTF engine shop visits increase significantly alongside expanding single-aisle fleets The report calls for greater parts availability, wider access to independent repair networks and more open aftermarket structures to improve aircraft time on wing A new industry study has warned that aircraft engine maintenance could become one of aviation’s key constraints as airlines prepare for a near-doubling of global fleets over the next two decades. Published by the International Air Transport Association (IATA) in partnership with consultancy Emerton, the report focuses on the engines powering the latest generation of single-aisle aircraft, including CFM’s LEAP and Pratt & Whitney’s Geared Turbofan (GTF), arguing that persistent supply chain pressures, limited repair capacity and restricted access to spare parts are already disrupting airline operations, and could intensify as fleet growth accelerates. At the height of the disruption in March 2025, 648 aircraft powered by GTF engines were grounded, representing roughly 28 percent of that fleet. Airlines affected have been forced into a series of operational workarounds, from extending leases on older aircraft to sourcing short-term replacements to maintain schedules. The underlying pressure points sit across several layers of the aftermarket. The study points to shortages of spare parts, constraints in engine repair slots, and a lack of available spare engines as key factors limiting how quickly aircraft can return to service. Those constraints are expected to come under increasing strain. Annual production of single-aisle engines stood at around 2,000 units in 2024, split between the two main engine families. Over the next decade, that figure is projected to rise towards 3,700 a year, driven by continued demand for fuel-efficient aircraft. As more of these engines enter service, maintenance demand is set to rise sharply. Shop visits for LEAP engines alone are forecast to climb from several hundred a year currently to more than 5,000 by 2040. GTF engines are also expected to see a steady increase, more than doubling over the same period. Willie Walsh, director general of IATA, said that while manufacturers are investing in additional capability, “capacity alone will not be enough” to resolve the issue, explaining how airlines need greater access to spare parts, more repair options and fairer conditions in the aftermarket. IATA believes several changes could ease pressure, including improving the availability of repairable parts, widening access for independent maintenance providers, and increasing transparency in the supply chain. It also suggests airlines and lessors may need stronger contractual protections to secure long-term access to parts and maintenance services. “Resolving today’s disruption is the immediate priority. But long-term resilience will depend on a more transparent, competitive, and collaborative aftermarket. Revisiting business models between aircraft and engine manufacturers is essential so that they better support operational resilience across the full aircraft lifecycle. The goal is to get engines back on wing faster, reduce avoidable disruption, and ensure that future fleet growth is supported by the MRO capacity and market access airlines need,” Walsh concluded.