Airbus has lost out to Boeing on a widebody order from Thai Airways, with some reports suggesting that this was in part due to disagreements over maintenance costs for the Airbus A350’s Rolls-Royce Trent XWB engines.

Thai Airways is thought to be behind an order for 45 Boeing 787-9s that the U.S. manufacturer published on its website next to an undisclosed customer in December 2023.

Furthermore, the flag-carrier is said to have opted for the General Electric GEnx engine over the Trent 1000 for its 787 aircraft. It had no such choice on the A350, of course, which is solely powered by the Trent XWB.

Regardless of whether this was a major influence on Thai’s aircraft selection, it highlights the longstanding question in commercial aviation of whether engine choice matters.

Clearly, airlines prefer to see competing engine offers on a platform, as it gives them more power when negotiating maintenance contracts, but how often that feeds into a purchase decision is harder to discern.

For example, 737NG sales were never hampered by its sole, CFM engine option, and while the 737 MAX has fared badly against the two-engine-type A320neo, factors such as the timing of the latter’s launch and the MAX’s well-documented problems are better explanations than engine choice.

In contrast, some operators are probably relieved that the neo does have another option given the issues affecting its Pratt & Whitney Geared Turbofan (GTF) engine. Indigo Airlines, for instance, switched to the CFM Leap for its neos after initially ordering GTF-powered aircraft.

Still, there is little evidence of a mass exodus: On in-service aircraft CFM had 53% of the A320neo-family engine market in 2019, and that share had barely shifted by this year, according to Aviation Week Network’s Commercial Fleet & MRO Forecast 2024.

There will be some movement, though, with the data predicting that CFM’s share will rise to 58% of A320neo aircraft by 2029.