The Jet Engine Efficiency Race: Pratt vs. GE

The quest for fuel efficiency leads to unconventional designs

Site 3B, 1 of 10 test sites at the GE Aviation Peebles Test Operation in Ohio. The tower houses fuel and other service lines required to operate an engine
Courtesy GE Aviation

(Updates second paragraph to clarify the origins of the materials used in the Leap engine’s fan blades.)

As airliners replace their fleets with more efficient models, jet engine makers are reimagining how planes are powered in a bid to score deals with Boeing and Airbus. The narrowbodied Boeing 737 Max and Airbus A320neo, slated to hit the skies over the next two years, are designed to take advantage of improved aerodynamics. CFM International and Pratt & Whitney are building engines meant to cut fuel use by 15 percent, though they’re taking different paths to get there. Jet engine sales in the next decade will total $500 billion, according to industry analyst Teal Group.

CFM, a joint partnership of General Electric and French aerospace company Safran, says it plans to close more than $8 billion in deals with airplane manufacturers for its new engine, the Leap, at the biannual Farnborough International Airshow that begins in England on July 14. First announced at the air show six years ago, Leap’s technology was developed mostly at GE’s global research center in upstate New York. GE has spent 20 years tinkering with a carbon composite used in engine fan blades, which can weigh one-third less than conventional aluminum ones, and this technology has started to make it into many of the engines it manufactures. The technique for the blades in the Leap engine, where made weaving flexible carbon fiber then cooking it with epoxy resin to yield a material as durable as metal, was initially developed by a subsidiary for Safran for its space applications. Other parts of the engine use materials with the low weight and heat resistance of ceramics. Three-dimensional printing has enabled GE’s team to create one-piece parts that used to come in 20 heavier pieces. “They’ve really taken it beyond in terms of composites,” says Wayne Plucker, an analyst at researcher Frost & Sullivan.

GE’s R&D operations last year cost $5.5 billion—twice what it spent a decade ago and more than 487 companies in the Standard & Poor’s 500-stock index. The funds cover everything from undersea oil facilities to bioengineering, but aviation is a top priority for GE, says Mark Little, who runs its global research center. “People around the world are flying a lot more, so the number of airplanes is going up by a factor of two over a decade,” he says. “Airliners are refreshing their entire fleets, because with that high-priced fuel, you simply can’t drag around the old engines.” GE’s revenue from aviation businesses is now 14.8 percent of its total, up from 10 percent three years ago.

Richard Aboulafia, vice president of analysis for Teal Group, says competition helped push the long-gestating GE engine to market. “They needed to reinvent their product offering to fight off a challenge from Pratt,” he says. Pratt’s new engine, the PW1000G, is based on a counterintuitive idea: increasing efficiency by spinning fan blades more slowly. The two main parts of any jet engine are the fan, which moves air through the engine, and the turbine, which burns fuel to spin the fan. The relationship between the parts, traditionally connected to the same shaft, is push-pull: Turbines produce more thrust when moving at top speed, but fans create more drag as they spin faster. Pratt’s new engines have geared turbofans, which allow the two components to move independently. The fan blades can slow down while the turbine spins furiously. Pratt declined to comment on its engine or competition with CFM.

The CFM Leap engine undergoes icing tests in Winnipeg, Man. The Leap is 15 percent more fuel-efficient than the previous CFM engine
Courtesy GE Aviation

Planemakers are split on which approach is best. Boeing, a longtime CFM customer, decided to design the 737 Max around the Leap engine. “We saw their technology road map and how they were bringing that to the Leap, and it made a lot of sense for us,” says Keith Leverkuhn, general manager for the Max line. Boeing already has more than 2,000 orders for the plane, bringing CFM’s total engines ordered to 6,770 as of June 30, an edge over Pratt’s 5,500, according to the companies.

CFM and Pratt are battling for Airbus’s business and have split its orders for A320neo engines, says aerospace consultancy Ascend. Airbus lets airlines choose their engines, and 36 percent of its A320neo inventory will carry the Leap, while 35 percent will use the PW1000G; the other 29 percent are unannounced. Aboulafia says CFM will eventually have to make a geared turbofan engine to keep pace with the efficiency Pratt’s design could achieve. For now, however, anyone in the market for a jet engine has a difficult decision to make, he says: “It’s rather remarkable that they are able to take such different paths and have such similar results.”

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