This year has seen CFM International ramping up the test programme for its next generation Leap-X engine and in July it will begin the first tests of its open rotor technology. Open rotors could offer significantly better fuel burn compared to turbofans.

On Saturday the first Leap-X core engine was "up and running" at GE's high-altitude test facility in Evendale, Ohio, says Chaker Chahrour, executive vice-president at CFM.

A full engine test should take place by 2012, after which it will enter the certification phase. Meanwhile, the full-scale Leap resin transfer molding composite fan is completing cross-wind and acoustics tests at GE's facility in Peebles, Ohio.

CFM outlined the plan for Leap-X, which is aimed at delivering a new turbofan to power Airbus A320 or Boeing 737 replacements by 2016, at last year's Farnborough air show.

 CFM Leap X
 

In the meantime, open rotor performance and acoustic tests will take place at NASA from July with additional tests taking place in Russian and French test facilities, says Chahrour.

This phase of testing is scheduled to be completed by late 2010/early 2011. If it sees "real promise" in the technology CFM will move to the flight demonstrator phase.

CFM admits however that open rotors have significant certification, installation and noise challenges compared with conventional turbofans. There is also a complex pitch-change mechanism for the blades, which are placed in different positions for take-off, cruise and the landing/reverse thrust phases of flight.

CFM also acknowledges that, along with the airframers, it will have to test public reaction to the open rotor technology. But Chahrour is convinced it will be positive: "I think it looks beautiful," he says.

Source: Flight Daily News