For years, aircraft engines have been treated as a distinct aviation asset class, bought, sold and leased through specialist providers. What's changing today is not their status as assets, but the extent to which engine availability is shaping airline strategy.
A combination of maintenance bottlenecks, spare parts shortages, durability issues and delayed aircraft deliveries has created a market in which access to spare engines can influence everything from fleet planning to growth ambitions. According to the latest engine market update from Jamie Davey of IBA, constrained spare engine availability continues to support strong lease rates across multiple engine platforms, even as values for some mature engine types have begun to stabilise.
The consequences extend well beyond engineering departments.
Revenue lost from an Aircraft on Ground (AOG) event caused by an engine fault or failure far outweighs the cost to lease in a spare engine," says Kane Ray, Head of General Aviation and Aftermarket at IBA.
That simple equation helps explain why airlines continue paying elevated lease rates for spare engines and why engine owners are enjoying one of the strongest markets in years.
The immediate driver of the shortage is the growing strain on the global maintenance network.
Historically, airlines could rely on a relatively predictable flow of engines through overhaul facilities. Today, operators are facing extended turnaround times as MRO providers contend with capacity constraints, labour shortages and continuing difficulties sourcing parts.
According to IBA, MRO pressures continue to drive demand for spare engines, particularly in the narrowbody market, while limited availability is keeping lease rates elevated.
The challenge is evident across all sectors of the industry. In regional aviation, the consultancy notes that shortages of critical PW127M components have pushed turnaround times beyond six months in some cases, increasing pressure on already stretched spare-engine pools and supporting higher values and lease rates.
The wider industry expects the problem to persist.
"Engine MRO bottlenecks are disrupting airline operations," warned Willie Walsh, Director General of IATA, arguing that the challenge could intensify as the latest generation of single-aisle fleets expands. He has called for improved access to spare parts, greater repair capability and more competition within the aftermarket.
Similarly, Jim Harris, co-leader of the aerospace and defence practice at Bain & Company, believes the industry faces a prolonged period of constrained maintenance capacity.
"Our analysis shows that aircraft engine MRO demand is likely to experience a near-term peak in 2026 and remain constrained through the end of the decade," he says. "Unless MRO companies act quickly to close this capacity gap, airlines will face higher costs to operate constrained fleets."
The growing scarcity of spare engines is increasingly affecting broader airline decision-making.
Ray notes that while airlines can offset some risks through warranty arrangements and maintenance agreements, prolonged engine disruptions have forced carriers to adjust long-term plans.
In recent years, several engine manufacturers have paid compensation to airlines affected by fleet groundings linked to engine-related issues. Yet compensation alone does not solve the operational challenge. Where spare engine availability is insufficient, airlines may be unable to retire older aircraft as planned or pursue intended growth strategies.
"This has therefore impacted broader airline growth, cost-saving, and product strategy," says Ray.
That observation highlights how engine availability has evolved into a strategic issue. Decisions once driven primarily by demand forecasts or aircraft deliveries are increasingly influenced by access to maintenance capacity and spare powerplants. The shortage is creating clear winners and losers.
Operating Costs
Airlines face higher operating costs and more complex maintenance planning. Engine owners, lessors and asset managers, meanwhile, are benefiting from robust demand and strong pricing.
Ray notes that when spare engine availability tightens, lease rental rates and market values rise accordingly.
"Market pricing of spare engines tells IBA that when availability becomes constrained, base lease rental pricing and market values increase," he says.
The strongest evidence can be found in the widebody sector.
According to IBA, the GE90-115B continues to deliver strong value performance as a result of limited spare availability, high maintenance demand and continuing delays to the entry into service of the Boeing 777X. Full-life values now exceed $35 million, while long-term lease extensions are reportedly generating between $250,000 and $300,000 per month.
Likewise, the Trent 700 powering the Airbus A330ceo has recorded significant value growth, with freshly overhauled examples trading between $17 million and $20 million.
The combination of high maintenance demand and limited availability has created a seller's market few would have predicted before the pandemic.
Aircraft production delays are further amplifying the trend. According to IBA, lagging deliveries from aircraft manufacturers are forcing airlines to retain older aircraft for longer, extending demand for existing engine fleets while simultaneously increasing maintenance requirements.
The result is a self-reinforcing cycle. Delayed aircraft deliveries keep older fleets in service. Increased utilisation drives maintenance demand. Longer maintenance queues create additional demand for leased spare engines. Scarce spare engines then push values and lease rates higher.
That dynamic is particularly visible in the widebody market, where deferred fleet renewal plans have sustained demand for mature engine programmes that might otherwise have entered a more gradual decline.
Engine manufacturers are working to address the problem.
CFM is rolling out durability improvements across the LEAP family. Pratt & Whitney continues to expand repair capacity and parts production while addressing its geared turbofan challenges. Rolls-Royce is pursuing initiatives designed to reduce maintenance turnaround times.
Yet few observers expect a rapid return to normality.
As maintenance demand continues to outpace available capacity, engine availability is likely to remain a significant constraint on airline operations and growth.
