How Pratt & Whitney's GTF Engine Quietly Grounded More Jets Than Any Crisis In Decades

Published Sep 17, 2026, 1:00 AM EDT Jack comes to Simple Flying with a lifelong interest in all things aviation. He holds a degree in Aerospace Engineering from Georgia Tech, and is a certified private and remote pilot. Beyond these experiences, Jack previously worked for a corporate flight department where he gained first-hand experience in the world of business aviation. Currently, Jack works in the professional services industry and continues to build his flight hours outside of work. Sign in to your Simple Flying account The most visible aviation disruptions usually arrive with a clear trigger. A pandemic closes borders, a war shuts down airspace, or a manufacturer discovers a defect across an aircraft fleet. The Pratt & Whitney geared turbofan (GTF) crisis led to inspections, delayed repairs, unavailable parts, and a shortage of replacement engines, leaving hundreds of otherwise usable aircraft parked for months. United Airlines CEO Scott Kirby recently estimated that between 800 and 900 aircraft worldwide were grounded because airlines could not obtain engines or critical components quickly enough. He warned that the shortage would persist for “many, many years,” identifying propulsion availability as one of the industry’s most serious long-term constraints. The central problem involves Pratt & Whitney’s PW1100G engines, which are also marketed as the Pratt & Whitney GTF, and powers a substantial portion of the Airbus A320neo family. Powder metal contamination discovered in certain engine components has required accelerated inspections and extensive maintenance. The resulting shop visits have lasted far longer than normal, while the limited supply of spare engines has prevented airlines from returning aircraft to service. The crisis has therefore become more than a technical problem. It is changing fleet planning, aircraft leasing, maintenance economics, and the value airlines place on operational reserves. The Groundings Became A Fleet-Wide Capacity Problem Credit: Mike Fuchslocher | Shutterstock The GTF was introduced as a major technological advance. Its geared architecture allows the engine’s fan and low-pressure turbine to operate at different speeds, improving efficiency compared with earlier turbofan designs. Pratt & Whitney promotes fuel savings of up to 20% per trip, alongside lower noise and reduced emissions. Those benefits helped make the engine attractive to airlines ordering large numbers of A320neo family aircraft. The difficulty emerged after the engines entered widespread commercial service. Powder metal contamination in certain components created the possibility of microscopic defects that could develop into cracks. The issue did not mean that every engine was immediately unsafe, but it required affected units to be removed, inspected, and, where necessary, repaired or replaced under an accelerated schedule. PW1100G Engine Specifications Fan diameter 81 inches (206 centimeters) Length 133.9 inches (3.401 meters) Weight 6,300 lb (2,858 kilograms) Bypass ratio 12.5:1 Takeoff thrust 33,110 lbf (147.28 kN) That process overwhelmed the available maintenance network. IATA reported that 648 Pratt & Whitney GTF-powered aircraft were grounded at the peak in March 2025, equivalent to 28% of the GTF-powered fleet. The aircraft were waiting for shop visits, spare engines, or parts. The effect on airlines was disproportionate because the A320neo family forms the backbone of many modern short-haul fleets. A grounded widebody can remove a long-haul route, but a grounded narrowbody can disrupt several daily services, regional connections, and the schedule feeding an entire hub. Carriers have responded by retaining older aircraft, extending leases, leasing additional jets, and reducing planned growth. The problem also emerged as manufacturers struggled to deliver new aircraft. Airlines that expected to replace older Airbus A320ceo family aircraft with new-generation models instead had to keep aging jets in service. This created additional maintenance exposure and reduced the spare capacity available to cover engine-related absences. Powdered Metal Turned Routine Maintenance Into Long-Term Downtime Credit: Coby Wayne | Shutterstock The GTF crisis is not defined only by the number of aircraft affected; its severity comes from the duration and complexity of the required work. An ordinary engine removal can be managed through scheduled maintenance planning. A campaign involving inspections of potentially contaminated parts requires specialized equipment, approved procedures, replacement components, and available technicians. A shop visit can therefore become a queue rather than a single maintenance event. Engines wait for disassembly, inspection, parts, repair slots, and final testing. Even after an airline secures a place in the maintenance sequence, the aircraft may remain grounded while the engine is being processed. The spare-engine shortage makes the situation worse. Airlines can often protect a schedule by installing a serviceable replacement while the original engine is in the shop. When spare units are unavailable, however, the aircraft itself becomes the waiting room. The carrier may have a functioning airframe, trained crew, airport slots, and passenger demand, but no approved propulsion system ready for use. United’s CEO described the problem as a shortage of engines rather than simply a shortage of aircraft. His estimate of 800 to 900 grounded aircraft included jets sidelined because they could not secure engines or essential components quickly enough. The figure illustrates how a component-level problem can immobilize a much larger asset. IATA’s forecast indicates why the backlog cannot be treated as a temporary disruption. The organization expects annual GTF shop visits to increase from approximately 1,000 in 2025 to more than 2,000 by 2040 as the installed fleet grows and engines enter heavier maintenance cycles. At the same time, LEAP engine shop visits are expected to rise from roughly 600 to 800 in 2025 to more than 5,000 by 2040. The forecast does not suggest that every future shop visit will produce a grounding, but it does show that maintenance demand will continue rising even after the immediate powder-metal campaign becomes less dominant. Airlines Are Paying for Efficiency They Cannot Fully Use Credit: Walter Cicchetti | Shutterstock The original business case for the GTF depended on lower fuel consumption. That advantage remains real when the aircraft is flying, but an engine that spends months off the wing cannot deliver fuel savings. The economic calculation also changes when airlines must lease replacement engines, retain older aircraft, or cancel flights. At IATA's annual meeting in June, airline executives described a widening gap between expected engine economics and actual ownership costs. WestJet CEO Alexis von Hoensbroech said newer engines were generating more unscheduled maintenance than anticipated, while Azul CEO John Rodgerson said some engines were not lasting as long as expected. The additional costs extend beyond the repair invoice. A carrier may pay for an engine lease while continuing to make payments on the grounded aircraft. It may also need to lease an entire aircraft, reposition crews, compensate passengers, or operate less efficient jets that consume more fuel. When replacement aircraft deliveries are delayed, the airline cannot easily remove older equipment from its fleet. Reuters reported that engine-related maintenance spending at six major US airlines increased by approximately 68% between 2019 and 2025, while flying hours rose by only about 10%. The data cover more than GTF-related work, and the figures do not identify the cause of each expense. Nevertheless, the increase reflects the broader cost pressure created by aging fleets, engine durability problems, parts shortages, and delayed aircraft replacements. The aftermarket has become especially expensive because newer engines have fewer used parts and less established repair history than older powerplants. Limited availability of serviceable components leaves airlines more dependent on original manufacturers and approved repair networks. This has also changed the balance of power between airlines and engine manufacturers. Airlines traditionally accept lower engine prices at the time of purchase in exchange for long-term maintenance arrangements. When the installed fleet becomes large, and the number of qualified repair alternatives remains limited, manufacturers gain considerable influence over parts pricing, shop access, and turnaround times. Pratt & Whitney Is Improving Output Credit: VanderWolf Images | Shutterstock RTX, Pratt & Whitney’s parent company, has reported measurable progress. During its first-quarter 2026 earnings call, RTX said PW1100G aircraft-on-ground levels were approximately 15% lower than at the end of the previous year. It also reported that PW1100G maintenance output increased 23% year over year, following 35% growth during the first quarter of 2025. The company has invested in additional maintenance, repair, and overhaul capacity, including a reported $100 million investment intended to accelerate the recovery. Pratt & Whitney has also expanded its MRO network and introduced initiatives intended to improve productivity, including greater use of automation at its Singapore facility. Those improvements matter, but they do not immediately erase the accumulated queue. A 15% reduction in groundings can coexist with high maintenance costs if aircraft that return to service are replaced by others entering inspections. The number of aircraft on the ground (AOG) is only one measure of the crisis. Turnaround time, spare-engine availability, parts inventory, and the number of aircraft approaching mandatory inspections are equally significant. RTX has said the GTF fleet management plan remains on track, and the company reported that GTF-powered aircraft had surpassed 2,700 deliveries by the first quarter of 2026. Pratt & Whitney also continues to receive new orders, with more than 800 GTF engine orders and commitments announced during the first seven months of 2026. That commercial demand indicates that airlines and lessors still see value in the engine’s efficiency and performance. The continued demand creates a difficult industrial balancing act. Pratt must support engines already in service while producing new units for aircraft deliveries. Material must be allocated between original equipment and the aftermarket. Every engine diverted toward a repair program can affect production planning, while every engine retained for new aircraft may leave an airline waiting longer for a replacement. IATA argues that adding MRO capacity alone will not solve the problem. The organization has called for greater parts availability, more approved repair options, fairer access to aftermarket services, and stronger long-term provisions for spare-parts pricing and supply. Nevertheless, in response to Simple Flying's request for comment, Pratt & Whitney explained that they are aggressively investing in MRO capacity and output, and have been successful. While the impact of the GTF issues is widespread, the company is making meaningful progress. "Reducing AOGs is a top priority and MRO output is the key to bringing them down. We continue to invest in our MRO facilities to increase capacity, for example in February we opened a $70 million 81,000-square-foot GTF MRO expansion at our Columbus Engine Center, and in April we announced a further $100 million investment across three MRO sites in Texas, Florida and Arkansas. GTF MRO output is up 300% since 2019, and up 43% year over year, supported by a 23% reduction in turnaround time. PW1100G-JM AOGs are continuing to trend downwards, falling over 25% year to date. We expect GTF-driven AOGs for Airbus A220s and Embraer E2 family aircraft to be cleared by year’s end." Spare Engines Have Become Strategic Assets Credit: CSWFoto | Shutterstock The most consequential lesson for airlines is not simply that one engine program experienced a major quality problem. It is that modern fleet planning often assumes a level of reliability and supply-chain responsiveness that the industry cannot always provide. For years, airlines often treated spare aircraft and engines as expensive operational insurance. Keeping additional assets available can reduce utilization, increase ownership costs, and make a fleet appear less efficient on paper. The GTF crisis has changed that calculation. A spare engine can protect an entire aircraft from months of inactivity, while a spare aircraft can preserve a route network when deliveries or maintenance schedules fail. The value of that reserve is especially valuable for airlines operating large fleets of a single engine type. Commonality simplifies training, scheduling, and parts management, but it can also concentrate risk. If a widespread technical issue affects the dominant engine across a fleet, many aircraft can become unavailable at the same time. A diversified engine portfolio may introduce complexity, but it can reduce exposure to one manufacturer’s maintenance system. Airlines are unlikely to abandon fuel efficiency, because fuel remains one of the highest operating costs and environmental requirements continue to tighten. However, procurement teams may place greater weight on time-on-wing performance, repair access, spare-engine guarantees, parts pricing, and the maturity of an engine’s maintenance ecosystem. Engine selection could increasingly resemble a long-term infrastructure decision rather than a narrow fuel-burn comparison. A powerplant that saves fuel during each flight may be less attractive if it requires more frequent removals, has limited repair alternatives, or exposes the airline to expensive leasing arrangements during a disruption. Reliability Will Become A Procurement Requirement Credit: Ian Dewar Photography | Shutterstock Pratt & Whitney’s GTF crisis has quietly grounded aircraft because the disruption is spread across thousands of maintenance decisions rather than concentrated in one dramatic event. The aircraft remain physically intact, but engines, parts, inspections, and repair slots determine whether they can generate revenue. The immediate recovery will depend on higher MRO output, improved parts supply, and a smaller inspection backlog. The longer-term response will be broader. Airlines will need to treat spare engines as strategic capacity, negotiate stronger aftermarket protections, and evaluate propulsion systems by full life-cycle cost. The next generation of fleet decisions will therefore be shaped by a question that extends beyond fuel efficiency: how reliably can an engine remain available when an entire industry needs the same parts, technicians, and repair facilities? The answer will influence aircraft orders, leasing strategies, maintenance contracts, and the resilience of airline networks for decades.