CFM Proceeds With Accellerated Development of Open Rotor Engine

They are looking to have a model in test this year, and a decision on if/how to proceed in the 2009-2010 time frame.

Seeing as how the open rotor, it's a lot like an advanced turboprop, would give something like a 25% improvement in fuel economy, the advantages are clear. The question is whether or not the related issues, particularly mounting and noise, can be resolved in an advantageous manner.