Rolls-Royce is in the final stages of building the world's largest jet engine, it has announced.
The so-called UltraFan demonstrator is being constructed at the aerospace giant's facility in Derby before its first run – on 100% Sustainable Aviation Fuel (SAF) – later this year. The engine has a fan diameter of 140 inches, with carbon titanium blades and a composite casing.
According to Rolls-Royce, which also has a UK base near Bristol, the engine offers a 25% fuel efficiency improvement compared with the first generation of Trent engines.