Nasa unveils shape-changing bird-like plane wing
Nasa has jointly developed a plane wing that can change shape during flight.
The US space agency says the new wing will "save millions of dollars annually in fuel costs, reduce airframe weight and decrease aircraft noise during take-offs and landings."
The wing features a seamless flexible edge that can move up or down more subtly than traditional hinged flaps.
The joint project involved Nasa, Air Force Research Laboratory and private tech firm FlexSys.
During six months of testing, an aircraft featuring the experimental control surfaces was flown at fixed flap angles ranging from -2 degrees to 30 degrees for data collection purposes, Nasa said.
But the flexible Adaptive Compliant Trailing Edge (ACTE) wing is designed to go through the full range of positions during a flight, making the operation of the wing much more like that of a bird.
Making the wing seamless allows for smoother airflow, which reduces friction and so cuts fuel costs.
FlexSys says its smart materials technology, which can be retrofitted to existing planes, can increase fuel efficiency by between 5% and 12%, and reduce noise on take-off and landing by up to 40%.
The conventional jet wing contains ailerons, flaps, slats and air brakes, all requiring mechanical parts that add weight and drag.
Prof Jeff Jupp, a former technical director for aircraft manufacturer Airbus and fellow of the Royal Academy of Engineering, believes this kind of flexible wing would have only "a very minor effect on improving fuel burn" for large passenger jets.
"Mechanical trailing edge flaps are only likely to be totally replaced on smaller aircraft such as business jets," he told the BBC.
As it is, the flexible wing is unlikely to replace the traditional wing any time soon as any new aviation technology has to go through rigorous safety testing that can take years.