Flight tests conclude for shape changing aircraft flap

by Air Force Research Laboratory Aerospace Systems Directorate

5/11/2015 - WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- A team of researchers from Air Force Research Laboratory, NASA and FlexSys, Inc., accomplished a long sought goal in aviation research April 22 with the last flight of the Adaptive Compliant Trailing Edge Flight Research program.

A radically new morphing wing technology called Flexfoil TM exceeded all expectations in flight testing. The ACTE program completed 22 research flights between Nov. 6, 2014, and April 22 at NASA Armstrong Flight Research Center at Edwards AFB, Calif.

Positive results from the flight tests indicate that Flexfoil TM, which can be retrofitted to existing airplane wings or integrated into entirely new airframes, is ready to revolutionize aircraft wing design. The technology enables engineers to reduce wing structural weight and to aerodynamically tailor the wings throughout the flight envelope to promote improved fuel economy and more efficient operations, while reducing environmental and noise impacts.

AFRL began work with FlexSys, of Ann Arbor, Mich., in 1998, through the Small Business Innovative Research program. AFRL and FlexSys developed and wind-tunnel tested several wing leading and trailing edge designs for various aircraft configurations through 2006.

In 2009, AFRL and NASA's Environmentally Responsible Aviation project agreed to equip a Gulfstream III jet with new flap surfaces designed and built by FlexSys, incorporating its proprietary Flexfoil Variable Geometry technology.

After seeing a morphing wing demonstration, AFRL Commander Maj. Gen. Tom Masiello said, "Here's another example of a successful government research partnership with small business to advance a very exciting aerospace technology for transition."

Flight-testing was key to proving the concept's airworthiness. The G-III was flown with its experimental surfaces at flap angles ranging from -2 degrees up to 30 degrees. Initial ACTE flight testing supported one of ERA's eight integrated technology demonstrations to explore design improvements for reducing drag, weight, noise, emissions and fuel consumption.

"The purpose of these tests," said ERA project manager Fay Collier, "was to see if flexible trailing edge wing flaps could improve aerodynamic efficiency and reduce the noise generated during takeoffs and landings."

Pete Flick, AFRL Program Manager at Wright-Patterson AFB, added, "We are thrilled to have accomplished all of our flight test goals without encountering any significant technical issues. These flights cap 17 years of technology maturation. The technology is now ready to dramatically improve aircraft efficiency for the Air Force and the commercial aviation industry."

Sridhar Kota, inventor of FlexFoil technology and founder of FlexSys Inc., was equally enthusiastic.

"Thanks to AFRL for its vision and leadership in recognizing the merits of our technology 17 years ago and supporting the development all the way through these flight tests, and thanks to NASA for its expertise and contributions in conducting the flight test," said Kota, who is also a professor of mechanical engineering at the University of Michigan.

Armstrong project manager Thomas Rigney said, "Our success was the result of a terrific partnership with the Air Force and FlexSys to flight test this promising new technology. I'm very impressed with the hard work and dedication of the team that made this possible, and I look forward to continuing our research."