Aircraft are becoming increasingly outdated and remaining in service for longer: there is a shortfall of 17,000, and it would take over 12 years to build them

For the first time, global revenue from passenger transport in the aviation sector is expected to exceed 1,000 billion dollars in 2025. Demand has reached a new high, with a record 5.2 billion people travelling by air. Revenue passenger kilometres (RPKs) have grown by 9% compared with the pre-pandemic peak in 2019.

However, as has been highlighted, those more than 5 billion passengers have been flying on increasingly ageing aircraft, as production capacity has failed to keep pace with this robust demand. At the start of 2026, there were around 17,000 unfilled aircraft orders on the books, a backlog that is expected to take over 12 years to clear at current production rates. In response to this shortage, airlines are keeping aircraft in service for longer and flying them more frequently. In 2025, the average age of the global fleet was just under 13 years, around a year and a half older than in 2024. The average flight hours per aircraft have increased by 2% year-on-year, with the utilisation rate expected to continue rising until deliveries catch up later in our forecast period.

It is pointed out that the shortage of aircraft is turning into a shortage of engines, with the industry becoming increasingly dependent on a limited number of systems and suppliers: LEAP and GTF, the two new-generation turbofan engines that dominate the single-aisle aircraft market, will account for over 75 per cent of global deliveries between 2026 and 2035. Against this backdrop, the MRO (Maintenance, Repair and Operations) market – which covers the products and services essential for day-to-day operations, and is estimated to be worth $136 billion in 2025 – is expected to grow to around $193 billion by 2036 (+40%), with potential further increases should production shortages persist.

Technical challenges relating to engines and wider supply chain constraints, including shortages of materials such as composites and titanium, are causing delays. Maintenance postponed during the pandemic and the 737 production halt between 2019 and 2023 have combined to create a ‘bow wave’ effect, contributing to capacity bottlenecks, longer lead times and fluctuating prices. Systems comprising large components have been the hardest hit, particularly engines.

To counter these persistent headwinds, airlines are managing their fleets strategically and seeking operational efficiency. With cost containment now essential, Oliver Wyman expects to see an increase in partnerships and acquisitions between airlines and maintenance service providers. Consumers will also face higher ticket prices due to rising costs across the entire system and the dynamics of supply and demand. Undoubtedly – as highlighted – significant investment is required – from upgrading technology to recruiting a replacement workforce, right through to strategic capital investment in spare parts – to ensure that the aviation sector can capitalise on growth whilst producing efficient aircraft.

The retirement factor

Another factor that has influenced the expansion of the fleet has been a wave of retirements among skilled workers. As the last members of the baby-boomer generation leave the workforce, taking their experience with them, the sector is struggling to attract and retain new generations of well-trained workers. Around 41 per cent of certified mechanics in the United States are over 60 years old, and some 45,000 mechanics are set to retire over the next decade. Air traffic control staff are also a cause for concern, with recruitment rates failing to bridge the gap left by retirements. In 2025, both North America and Europe experienced flight delays and cancellations due to a shortage of air traffic controllers. Retirements are also affecting management, and a leadership vacuum is an emerging concern. A slowdown in recruitment during the 2000s and 2010s has led to fewer middle managers with the experience and industry knowledge needed to take over from the previous generation.