The International Air Transport Association (IATA), in partnership with consultancy Emerton, published a study on 24 June examining supply-chain bottlenecks in the maintenance, repair and overhaul (MRO) of latest-generation single-aisle aircraft engines. The report, titled Single Aisle Aircraft Engines MRO: Strategic Levers to Address Supply Chain Challenges, focuses specifically on CFM International’s LEAP engines and Pratt & Whitney’s Geared Turbofan (GTF) engines.
According to the study, engine durability issues, shortages of spare parts, limited availability of spare engines, and constrained aftermarket access are creating costly operational disruptions for airlines worldwide. These pressures reduce engine time on wing, increase demand for shop visits, and complicate maintenance planning for carriers such as Delta Air Lines, IndiGo, and Air France-KLM.
Grounded Fleet and Growing Demand
The number of GTF-powered aircraft grounded while awaiting engine shop visits, spare engines, or parts peaked at 648 in March 2025—representing 28% of the global GTF fleet. Affected airlines have been forced to retain older aircraft, extend leases, or lease additional planes to adjust capacity. The challenge is expected to intensify as the fleet of latest-generation single-aisle aircraft expands. In 2024, engine deliveries totaled 2,000 units (800 GTF and 1,200 LEAP). Between 2030 and 2040, deliveries are projected to stabilize at around 3,700 per year (1,200 GTF and 2,500 LEAP).
This acceleration will drive a sharp increase in maintenance demand. Annual shop visits for LEAP engines are forecast to rise from approximately 600–800 in 2025 to more than 5,000 by 2040. For GTF engines, visits are expected to climb from 1,000 to over 2,000 in the same period.
Strategic Levers for Resilience
IATA Director General Willie Walsh emphasized the urgency: “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.”
The study identifies four key actions to improve resilience across the value chain:
- Increase engine parts availability by accelerating development and approval of repair solutions to reduce scrap rates, expanding licensed production of critical components, and increasing access to used serviceable material from engine teardowns.
- Ensure fair access to the MRO market by removing barriers that limit independent MRO participation and supporting fair access to parts, repair information, and tools. This is provided for in the IATA-CFM agreement, signed in 2018 and renewed in January 2026, which includes a good-practice model for customer choice, regulatory-approved non-OEM parts and repairs, and fair access for third-party providers such as Lufthansa Technik and GE Aerospace.
- Secure long-term access to spare parts by including provisions in aircraft and engine acquisition decisions that guarantee predictable pricing and allow airlines to assign parts access to their chosen MRO providers, including independents.
- Adopt industry-wide best practices requiring all OEMs—engine, airframe, and component—to adopt transparent and competitive aftermarket principles that support customer choice and the use of approved alternative parts and repairs certified by regulators.
Coordinated Action Required
Delivering these priorities will require coordinated action across the aerospace supply chain. Airlines, aircraft and engine manufacturers, MRO providers, and lessors must collaborate to improve parts availability, expand repair options, and better align maintenance capacity with operational needs. Walsh concluded: “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.”
For airlines and lessors, the study underscores the importance of proactive maintenance planning and strategic partnerships. As narrowbody fleets expand, the MRO bottleneck could become a defining operational challenge of the next decade. Industry stakeholders are urged to act now to avoid compounding disruptions as delivery rates climb.
