The International Air Transport Association (IATA), in collaboration with Emerton,released a new study examining bottlenecks in the maintenance, repair and overhaul (MRO) of latest-generation single-aisle aircraft engines on Wednesday, 24th June.
The study specifically referred to MRO for LEAP engines from CFM and Geared Turbofan (GTF) engines from Pratt & Whitney.
Titled Single Aisle Aircraft Engines MRO: Strategic Levers to Address Supply Chain Challenges, the study highlights how engine durability issues, spare parts shortages, limited spare engine availability, and constrained aftermarket access are disrupting airline operations.
These pressures are creating costly operational challenges, including reduced engine time on wing, increased demand for engine shop visits and more complex airline maintenance planning.
As IATA director-general Willie Walsh put it: “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. Manufacturers are investing in additional capacity, but capacity alone will not be enough. Airlines need better access to spare parts, more approved repair options, fair access to MRO capacity and greater competition in the aftermarket.”
Tale of the tape
The number of grounded Pratt & Whitney GTF powered aircraft peaked in March 2025 at 648. 28 percent of the GTF-fleet.
These aircraft were awaiting engine shop visits, spare engines or parts. Affected airlines have had to adapt their fleet plans, including by retaining older aircraft, extending leases or leasing additional aircraft, and adjusting capacity.
The challenge is expected to grow as latest-generation single-aisle fleets expand. In 2024, single-aisle aircraft engine deliveries totalled 2,000 (800 GTF and 1,200 LEAP).
Between 2030 and 2040, deliveries are expected to be stable at about 3,700/year (1,200 GTF and 2,500 LEAP).
This acceleration of deliveries will significantly increase maintenance demand, as annual shop visits are forecast to rise from around 600–800 in 2025 to more than 5,000 by 2040 for LEAP engines, and 1,000 to more than 2,000 for GTF engines.
What may be done in the meantime
While there is no single solution to alleviate the current situation, several actions have been identified where efforts across the value chain could deliver better resilience in the near and longer-term:
- Increase engine parts availability: Make more parts available by accelerating the development and approval of repair solutions to reduce scrap rates, expanding licensed production of critical components, and increasing access to used serviceable material recovered from engine teardowns;
- Ensure fair access to the MRO market: Remove barriers that limit independent MRO participation and support fair access to the parts, repair information and tools needed to develop additional capacity. This is provided for in the IATA-CFM agreement, signed in 2018 and renewed in January 2026. The agreement includes a good-practice model for supporting customer choice, regulatory approved non-OEM parts and repairs, and fair access for third-party MRO providers;
- Secure long-term access to spare parts: Including provisions in aircraft and engine acquisition decisions to secure long-term access to predictable spare parts pricing would provide greater certainty for airlines and lessors. This includes protections that airlines can assign to their chosen MRO providers, including independent providers; and
- Adopt industry-wide best practices: All OEMs (engine, airframe and component) should adopt transparent and competitive aftermarket principles that support customer choice and the use of approved alternative parts and repairs certified by regulators.
Better coordination is necessary
Delivering these priorities will require coordinated action across the aerospace supply chain.
Airlines, aircraft and engine manufacturers, MRO providers and lessors must work together to improve parts availability, expand repair options and better align engine maintenance capacity with airline operational needs.
Walsh said: “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.”
