has opened Paris with a shot across the bow of competitor Pratt & Whitney, claiming its engine has up to 3% lower specific fuel consumption (sfc) than the rival geared turbofan on the family.
“The Leap will go into revenue service on the A320NEO 1% better than the competition, based on testing to date,” Chaker Chahrour, executive vice president of CFM told the press here on Saturday.
“And it will retain that 1% better than the competition, which when you integrate over time adds up to another 1%,” he says. “And on the A321, because of the longer legs and our better cruise sfc bucket, we get another 1%. So on the A321, 1 plus 1 equals 3.”
CFM calculates the 3% better fuel burn on the A321NEO than the PW1100G is worth $2 million per aircraft net present value (NPV). In addition, Chahrour says, the Leap’s longer time on wing will translate into two fewer shops visits over the life of an engine, “for the bulk of another $2 million” in NPV.
The/ joint venture calculates an NPV advantage of $4 million per aircraft on the A320NEO for the Leap-1A, up from the $3.5 million claimed at last year’s Farnborough show.
Lower line maintenance costs for the fan case-mounted accessories make up the rest of the calculated advantage. “The line replaceable units do not see the temperatures” of the core-mounted accessories on the geared turbofan, he argues.
CFM’s claims are based on the results of just-completed tests of the third eCore demonstrator — comprising the high-pressure compressor, combustor and high-pressure turbine of the Leap-1. The core completed 203 hr. of tests with “better component efficiencies than expected,” Chahrour says.
Composite fan-blade and low-pressure turbine tests have also produced “excellent results,” he says. The first Leap-1A, meanwhile, is on schedule to begin ground tests “in the fall.” CFM is aiming for a 15% sfc reduction over the-5B engine now powering the A320.
CFM is making much of the Leap’s performance advantage versus the PW1100G. This is based on the incorporation of variable bleed valves (VBV), first introduced on the largerand GENx. These are eight doors that extend into the flow entering the compressor to divert debris into the bypass duct.
The fan spinner is designed to push heavier particles to the outside of the flow entering the core and at lower power, during taxiing or reverse thrust when debris is highest, the VBVs open to reject particles to the fan stream, reducing erosion of the compressor blades over time.
“We get at least 1% better performance retention” than the PW1100G, says Gareth Richards, Leap program manager. The VBVs are closed at high power and in the cruise to avoid a performance penalty.
Performance and durability will be confirmed over a planned 60 test engines – 28 for ground testing at CFM and 32 for flight testing by customers – with 40,000 cycles expected to be accumulated before entry into revenue service, compared with around 10,000 cycles for the CFM56-5B/7B program
CFM, meanwhile, is gearing up to produce 1,700 engines in 2020, almost all Leap-1s. This will be an increase from the 1,500 engines planned for this year and 1,540 for 2014, all CFM56s. The transition to Leap will begin in 2016.
Already the Leap makes up almost half of the roughly 10,000 engines the joint venture has in backlog: 1,392 Leap-1As for the A320NEO, 2,470 -1Bs for theand 760 -1Cs for the .