Originally Posted by
lidarheadache
I wonder what ever happened to the geared turbofans that both GE and P&W were so hot on in the late 80's when fuel prices went through the roof? They both had test a/c with one on the back that was about 30-35% more efficient and met noise limits. They were supposed to solve the TP's speed limitations, weren't they?
see:
http://en.wikipedia.org/wiki/Propfan
PW is currently testing a narrow-body sized geared turbofan, and will be certifying it in the upper-RJ thrust range. The bombardier C-series and the Mitsubishi RJ will both use this engine, and I'm betting others will get on board fast.
On that note, the Mitsubishi RJ looks pretty good on paper...they fixed most traditional RJ pax annoyances and threw in a lot fuel-effecient technology.
I think GE and Rolls are holding out for more technology before comitting to GTF vs. Open Rotor, but they will have to decide before the Boeing and Airbus next-gen narrowbody designing starts in earnest.