GTF vs. LEAP will be a 'big battle that will range for a long period of time.'
As CFM International and Pratt & Whitney compete head-to-head on the Airbus A320neo program, there is a longstanding argument between the two engine manufacturers somewhat reminiscent of a school cafeteria scrap over who’s the coolest kid—er, engine—in the class.
CFMI’s LEAP-1A and Pratt’s PW1100G geared turbofan (GTF) are both options on the re-engined A320neo, the only aircraft program on which airlines can choose between the two next-generation engines. Both CFMI and Pratt agree that a cooler-running engine is better. Cooler, they agree, means greater efficiency and lower maintenance costs. And both say with certainty that the competitor’s engine will operate at a higher temperature.
I certainly don’t have the engineering background to settle the dispute. And eventually the proof will be in the pudding. Once both engines are operating on the A320neo, airlines will find out which engine is the coolest.
But in covering both companies, I’ve had a front row seat to this ongoing fracas, which was on full display at the 2014 Singapore Airshow.
“Our engine is going to operate cooler,” CFMI EVP Chaker Chahrour told reporters during a briefing in Singapore. “Our better cooling technology is going to drive our engine to be cooler.”
Pratt president-commercial engines David Brantner countered during a briefing in Singapore that the GTF will be “much cooler” than the LEAP.
The source of the dispute revolves around whether CFMI is using non-traditional materials to construct the LEAP-1A. Pratt believes its gear on the PW1100G allows it to use fewer and smaller parts, requiring less work and less heat. “The way we’ve architectured our engine means we’ve not had to put super-advanced materials in it,” Brantner explained, adding that the PW1100G uses “conventional materials.”
Pratt commercial engines marketing director Jim Speich said the company is “staying out of exotic materials” on the GTF. The PW1100G’s “efficiency comes from propulsive efficiency rather than exotic materials,” Speich explained.
Chahrour said “the argument [with Pratt] started when they wanted to build a case that we wanted to use more exotic materials [on the LEAP compared to the GTF]. But the truth is we don’t use more exotic materials.”
He explained that within the LEAP-1A, “each turbine blade is seeing air flowing around it … We take air from the compressor and actually cool” the engine. The LEAP blades also have small holes, which “gives you a cooling effect,” Chahrour said.
With neither engine yet in service, don’t expect this spat over who’s “cooler” to be settled anytime soon. As Pratt president Paul Adams told me in Singapore, GTF vs. LEAP will be a “big battle that will range for a long period of time.”