Forget cycling to work - how about a human-powered helicopter? Engineering students at the University of Maryland have successfully tested
Gamera, a massive pedal-powered chopper.
Gamera has four 13-metre wide rotors, one at each end of its 18-metre wide cross-shaped carbon-fibre frame, but weighs less than 100kg - including the human pilot, Judy Wexler, who sits in the middle and provides power through both hand and foot peddling. Wexler successfully lifted off after two days of testing, managing to get several inches off the floor for about four seconds. "We're ecstatic," says Brandon Bush, Gamera team leader.
Though the team of more than 50 students were pleased to finally get airborne, they failed to achieve their ultimate goal of claiming the American Helicopter Society's Sikorsky Prize. The prize, worth $250,000, requires a human-powered helicopter to hover for a full minute while remaining within a 10-metre square. It must also fly higher than three metres at one point.
Only a few attempts have been made at claiming the prize since it was launched in 1980. The previous best result, known as
Yuri 1, used a similar but smaller design to Gamera and achieved an altitude of 20 centimetres for just under 20 seconds, though an unofficial attempt achieved 70 centimetres for 24 seconds.
Human-powered aeroplanes have been successful in the past, such as when the
Gossamer Albatross flew across the English Channel in 1979, but flying a helicopter is more challenging as they must be much lighter and more efficient. Both Gamera and Yuri 1 achieve flight by exploiting the ground effect, an increase in lift that occurs when an aircraft flies close to the ground. Gamera actually uses an "extreme" ground effect, with the rotors less than five per cent of their length off the ground.
Bush hopes to fly Gamera again in the future, but says it's hard to find spaces large enough for testing. "The major drawback that prevented us from going much longer was the proximity to one of the walls," he says. Testing outside is not a viable alternative, since even small gusts of wind could send the helicopter veering off course."Hopefully people will see our efforts and maybe donate some hangar space," he says.