EasyJet Wants More Work on Open Rotor Engines

Also called advanced turboprop or unducted fan, these engines promise a 30%+ increase in efficiency, more for short hops, which is EasyJet's bread and butter, so it's challenging the engine and airframe manufacturers to get it working on a narrow body airliner.

The technology works, it was demonstrated over 20 years ago, but the issues are complexity, reliability, and noise.