Last week ANA said fan blades in the turbines of Trent 1000 engines on aircraft making short-haul flights were suffering from corrosion faster than expected.
As a result, the airline said it could cancel up to 300 flights as it takes aircraft out of service for repairs to the engines.
Mr Bourne said: “It’s another thorn in the already difficult near-term investment case for Rolls, but it’s not a massive problem. We think ANA panicked last week when it signalled they may cancel up to 300 flights. Now it sees the impact is not as bad, although it needs to accelerate the maintenance programme.”
The corrosion is a known problem, but was not forecast to affect engines on ANA planes on short-haul routes so soon. This is because they run at lower temperatures and encounter fewer chemicals, which contribute to the corrosion through a process known as “sulfidisation”, than jets flying on long-haul flights.
ANA has since said it will only cancel a fraction of the number of flights first announced. It will also replace engines on a handful of short-haul jets in its fleet, while accelerating repairs on its fleet of 50 Dreamliners to replace the corroded turbine blades. This process could take three years to complete.