Pratt Engine Crisis: United CEO Estimates Up to 900 Jets Grounded

Between 800 and 900 aircraft worldwide may be grounded because airlines cannot obtain engines or critical components quickly enough, according to an estimate from United Airlines CEO Scott Kirby. He warned that the broader engine shortage not solely the Pratt & Whitney geared-turbofan problem could persist for “many, many years.”

The distinction matters. Kirby’s estimate covers multiple engine and component constraints across the industry. Within that total, Pratt & Whitney’s PW1100G maintenance campaign shows how a problem inside an engine can remove an otherwise usable Airbus A320neo-family aircraft from service: without a serviceable replacement engine, the entire jet remains parked while its powerplant awaits inspection, parts, repair capacity or final testing.

One component problem became a fleet-capacity problem

Powder-metal contamination in certain PW1100G components created the possibility that microscopic defects could develop into cracks. Affected engines therefore require accelerated removal and inspection, followed by repair or component replacement where necessary.

Removing an engine is only the beginning of that process. Each unit must move through disassembly, inspection, parts disposition, reassembly and testing. The rate at which aircraft return to service consequently depends on the slowest constrained resource, which may be a replacement part, an approved repair, a technician, a shop position or a spare engine.

That systems-level constraint explains why aircraft availability can deteriorate even when the airframe, crew and passenger demand are all present. An airline can install a spare engine and return the aircraft to its schedule, but only if a suitable spare is available. Otherwise, the aircraft effectively becomes the waiting area for the engine-maintenance process.

The International Air Transport Association reported that grounded Pratt & Whitney GTF-powered aircraft peaked at 648 in March 2025, representing 28% of that fleet. Those aircraft were awaiting shop visits, spare engines or parts. That figure is specific to GTF-powered aircraft and should not be conflated with Kirby’s wider estimate of 800 to 900 jets affected by engine and component shortages.

More maintenance output is beginning to reduce groundings

RTX, Pratt & Whitney’s parent company, reported in its first-quarter 2026 earnings call that PW1100G aircraft-on-ground levels were approximately 15% below the end of the previous year. It also said maintenance output had risen 23% year over year, following 35% growth in the first quarter of 2025.

Pratt & Whitney has reported a different set of progress measures covering its GTF maintenance network. The company said output had increased 300% since 2019 and 43% year over year, supported by a 23% reduction in turnaround time. It also said PW1100G-JM groundings had fallen more than 25% year to date. These percentages use different baselines, periods and scopes, but they point in the same direction: more engines are moving through the repair system, and the grounded fleet is declining.

Capacity additions include a $70 million, 81,000-square-foot expansion at the Columbus Engine Center that Pratt said opened in February. The company also announced another $100 million investment across maintenance sites in Texas, Florida and Arkansas in April. Automation is being introduced across the maintenance network as well, including robotic inspection and assembly processes intended to reduce labor hours and processing time while retaining required human verification.

Repair shops alone cannot clear the constraint

Adding floor space and equipment does not guarantee that completed engines leave at the same rate. Shops still need serviceable parts, approved repair methods and trained personnel. Pratt must also divide industrial resources between supporting the installed fleet and supplying engines for newly built aircraft. More than 2,700 GTF-powered aircraft had been delivered by the first quarter of 2026, according to RTX, so the long-term maintenance population continues to expand.

Airlines have managed the shortage by retaining older aircraft, extending leases, leasing additional jets and reducing planned growth. Those responses add cost or limit capacity, but they can preserve schedules when a newer aircraft is unavailable. Passengers may experience the consequence as fewer seats or disrupted schedules rather than as an engine-maintenance issue.

The demand curve will keep pressure on this system after the current inspection campaign subsides. IATA expects annual GTF shop visits to rise from approximately 1,000 in 2025 to more than 2,000 by 2040. Pratt’s higher output can reduce today’s backlog, but a durable recovery will depend on whether parts supply, approved repairs, spare-engine availability and maintenance capacity expand quickly enough to support both the existing fleet and thousands of future shop visits.

By Thomas Caldwell — AMI’s senior editor for mechanical and mobility engineering, covering vehicle electronics, systems integration, electrification, chassis systems, propulsion, and safety policy.