Joined by top U.S. transportation officials, Boeing and American Airlines showcased the 737-800 “ecoDemonstrator” flying testbed at Washington Reagan National Airport on September 18. Boeing had flown the aircraft from its flight-test facility at Glasgow, Montana, the preceding day using a biofuel blend made partially from used cooking oil.
Boeing and several partner companies are testing a suite of “environmentally progressive” technologies and alternative jet fuel on the new aircraft, which American Airlines has made available on loan before its scheduled delivery in November. The FAA provides funding for one of those technologies–an “adaptive” wing trailing edge–under its Continuous Lower Energy, Emissions and Noise (Cleen) program, described as the principal environmental effort of the Next Generation Air Transportation System.
The adaptive trailing edge deflects into an optimum shape during each flight phase, improving fuel consumption with optimum aerodynamics and reducing noise on takeoff by improving the aircraft’s climb performance. Other technologies aimed at reducing fuel burn and noise on the ecoDemonstrator include a variable-area fan nozzle supplied by CFM International, manufacturer of the aircraft’s CFM56-7B turbofan engines; an active engine vibration control system from Hutchinson Aerospace; a regenerative hydrogen fuel cell from Japan’s IHI; and a “flight trajectory optimization” system for display on Apple iPad tablet computers, under development by Boeing subsidiary Jeppesen. The aircraft also features carpet tiles made from recycled materials.
Boeing engineers said the ecoDemonstrator has logged approximately 70 flight hours and will return to the company’s facilities in Washington state for more testing. “The indicators are there for fuel reductions,” Billy Glover, Boeing vice president of environment and aviation policy, said of the test results to date. Jeanne Yu, the manufacturer’s director for environmental performance, said noise testing in Glasgow has demonstrated “a few dB delta” change using the adaptive wing trailing edge and variable-area fan nozzle. Boeing will restore the aircraft to its original configuration before delivery to American Airlines.
Under the Cleen cost-sharing program, the FAA and Boeing hope to achieve a 2-percent reduction in aircraft fuel consumption using both the adaptive wing trailing edge and ceramic matrix composite acoustic engine nozzles. Plans call for the engine nozzles to fly on a 787 Dreamliner in the second of a series of ecoDemonstrator tests. Boeing said it will conduct ground tests on a Rolls-Royce Trent 1000 engine next month, followed by flight testing next year.
