Oliver Wyman, the New York-based consulting firm, asked participants in its 2026 MRO Survey when engine overhaul span times will return to pre-pandemic conditions. The responses show that most respondents expect the recovery to take until 2028 or later.

Four percent of respondents said overhaul span times have already normalized. Another 5 percent expect normalization within 12 months, in 2026, and 9 percent expect it between 12 and 18 months out, by the first half of 2027. Together these groups make up 18 percent of respondents.

The largest share, 35 percent, expects normalization in more than 18 and up to 36 months, which places recovery between the second half of 2027 and 2028. A further 29 percent expect it to take more than 36 months, into 2029 or later. Eighteen percent do not expect engine overhaul span times to recover to pre-pandemic conditions. The question excluded 6 respondents whose companies had not experienced significant span time challenges.

Oliver Wyman's accompanying analysis links the delays to shortages of advanced materials, long lead times for castings and forgings, and limited supplier diversification for critical engine parts. It also cites newer engine platforms that have taken longer than expected to reach mature reliability, and proprietary repair solutions controlled by manufacturers. Nearly 30 percent of survey participants do not expect a full supply chain recovery for more than three years.

The firm notes that a small number of specialist providers perform most engine maintenance and that capacity cannot be added quickly because new engine types require dedicated tooling, workforce training and manufacturer certification.

Source: Oliver Wyman - https://www.oliverwyman.com/our-expertise/insights/2026/sep/aviation-engine-availaibility-bottlenecks.html