Pratt & Whitney Pitches GTF Cost Savings

Pratt & Whitney completed ground and flight testing of its PurePower PW1000G geared turbofan demonstrator engine, which the U.S. engine maker promises will provide major fuel cost savings for future customers.

The latest phase of the PW 1000G developmental testing was jointly completed with Airbus Industrie on an A340-600 development aircraft and included 27 flights and 76 hours of flight testing, the first of which was undertaken in October 2008.

Airbus was the first airliner manufacturer to fly the PurePower PW1000G demonstrator engine on its own flight test aircraft. The test results will contribute to the company's long-term research and technology assessment of new engine configuration developments.

The PW1000G features Pratt & Whitney’s patented geared turbofan technology, which is geared to provide “double-digit reductions in fuel burn, engine noise, environmental emissions and operating costs,” according to the company. Both airlines and manufacturers say that a 15 percent improvement is required for new investment but Pratt suggests it provides a 20 percent.

The PurePower PW1000G engine uses a state-of-the-art gear system allowing the engine’s fan to operate at a different speed than the low-pressure compressor and turbine. The result is a step-change improvement in fuel efficiency and a slower fan speed for much lower noise. The PurePower PW1000G engine is an all new centerline engine that includes next generation technology in every major module.

“The combination of the gear system and an all-new advanced core delivers major improvements in fuel efficiency and environmental emissions and a 50 percent reduction in noise,” the U.S. engine manufacturer claims.

Pratt & Whitney says it has successfully tested the advanced high pressure compressor and low emissions combustor technology of the PW1000G engine, an all new centerline engine that includes next generation technology in every major module.

Speaking recently at an event in Toulouse, France, which marked the end of the current geared turbofan demonstrator engine’s flight testing on Airbus's A340-600 flying testbed, Bob Saia, P&W vice-president next-generation product family, said “the PurePower PW1000G demonstrator engine successfully demonstrated the performance and operational benefits of the engine’s unique gear system.”

The Airbus flight testing followed Pratt & Whitney’s own ground and flight test program, during which the engine completed 250 hours of ground testing and 44 hours over 12 flights on Pratt & Whitney’s Boeing 747SP flying test bed.

Saia said, “the PW1000G demonstrator engine successfully completed all test objectives. It is truly unprecedented to complete this amount of testing on a technology demonstrator engine. We were able to complete all flight test objectives with flawless engine operation. The Airbus A340 flight test program included engine test evaluations normally conducted for a production engine certification.”

The most recent flight evaluation assessed in-flight performance, engine handling, in flight acoustics and aircraft installation of the demonstrator engine. The prototype engine has been removed from the A340-600. Pratt & Whitney will now analyze the flight test data and use it over the next several months to tweak the engine’s design.

“One of a kind demonstrator engines like this are typically designed to test for approximately 100 hours,” Saia added. “It is extraordinary that the PW1000G demonstrator engine completed 406 hours of testing, including a total of 120 hours in flight. The engine performed exceptionally throughout the program, demonstrating both performance and reliability under extremely challenging tests such as high altitude aircraft flight maneuvers exceeding two G’s of acceleration force. Thousands of data points taken during this test program will enable our engineers to optimize the engine as we enter detailed design mid-year.”

Completion of the ground and flight test program clears the way for detailed design of the first production PW1000G GTF engines in mid 2009 for the Mitsubishi MRJ Regional Jet and the Bombardier CSeries mainline aircraft. Both aircraft are due to enter service in 2013.

The PurePower PW1000G engine was selected in 2007 as the exclusive powerplant for the new Mitsubishi Regional Jet and the Bombardier Cseries commercial transport.

Mitsubishi announced its first customer for the next generation regional jet in March 2008, with an order from All Nippon Airways. The CSeries was launched in July 2008 with a letter of interest for up to 60 aircraft from Lufthansa although analysts noted recently that the year ended without a second customer. They suggest that the new technology and uncertain economy are causing most airlines to take a wait and see attitude.

Stephen Finger, president of Pratt & Whitney until his retirement late last year, said: “by our calculations, airlines buying the Mitsubishi Regional Jet or the Bombardier CSeries with our Geared Turbofan engine will save between $1 million and $2 million dollars per year, per aircraft, in a combination of lower fuel costs, maintenance costs and noise and other emissions fees.

“This engine is real. It is available today on the Mitsubishi Regional Jet and the Bombardier CSeries…The block fuel benefit for these two aircraft is 20 percent each better than other aircraft flying today and up to 40 percent better than older aircraft in the same size range and class. And I’ll tell you, most of that benefit comes from the geared turbofan engine. It’s available in these aircraft and it’s available in 2013,” he added.

Pratt & Whitney believes its new, fuel-efficient geared turbofan engine will be able to power all the next generation of turbofan-powered airliners. Company officials say the geared turbofan can be scaled up to produce 90,000 to 95,000 pounds of thrust, making it powerful enough for use on the largest in-development commercial jetliners.