Boeing has flown a Boeing 737-900ER equipped with a revised version of the CFM International CFM56 nacelle in the number one (left-hand) position.
The engine nacelle is elongated compared with the current CFM56-7B, which is the standard engine equipping Boeing's Next Generation 737 family.
The CFM56-7BE is expected to fly under the wing of GE's 747-100 test bed in February 2010, followed by 737 flight testing beginning in October 2010.
The CFM56-7B Evolution is being developed to deliver a 1% fuel efficiency improvement for the 737 family when it enters service in 2011. Minor aerodynamic tweaks to the airframe are expected to deliver a further 1% gain in performance.
The CFM56-7B Evolution incorporates reshaped blades and vanes in the high- and low-pressure turbines to increase airflow through the engine and reduce operating temperature, director of CFM56 Boeing programmes Robyn Brands said at the Paris air show in June.
It introduces changes to the engine nozzle and plug, and removes about 9% of engine aerofoils from the high- and low-pressure turbines to reduce maintenance costs by up to 4%.
© Joe Walker