It was last October when Gizmag first reported on the exploits of AeroVelo, the lastest in a long line of flyers, high and otherwise, to vie for the US$250,000 Sikorsky Prize. To claim the bounty, a human-powered helicopter must fly for over a minute and attain an altitude of over 3 m (9.8 ft) while remaining within a 10 m x 10 m (33 x 33 ft) box. On June 13, AeroVelo's Atlas helicopter did precisely that.
The Atlas set a world record with its flight time of 64.11 s, flew to a height of 3.3 m (10.8 ft), and deviated from an effective standstill by only 9.8 m (32 ft). The flight consisted of a 10-second ascent followed by a very gradual return to Earth, during which the pilot had to work against drift.
AeroVelo says the record-breaking Atlas has changed significantly since the version which flew for 4 seconds last August, no doubt spurred by two crashes during testing earlier this year. However, the team was always going to be one to watch given its prior achievement of breaking the college-level human-powered land speed record with its Vortex bicycle in 2011.
The prize-winning Atlas has four rotors arranged in a square formation. These are mounted on shorter arms than in previous models, so that the rotors now overlap. The main structure of the aircraft (I think we can call it that now) is composed of carbon fiber strengthened with Vectran braided cord. The ribs and skin of the rotor system are made from polystyrene, balsa wood and polyester film.
The drive system is bascially a bicycle. With gusto, the pilot pedals from the center of the vehicle, reeling in four Vectran cords from their spools around the rotor hubs, spinning the rotors themselves into action. A flywheeel evens out the power delivery, though the team points out that this is not capable of storing energy ahead of takeoff.
Control surfaces on the rotors' tips have been replaced with what AeroVelo describes as a "leaning/thrust-vectoring control system," in which the bicycle frame is connected to each rotor shaft (with yet more Vectran) so that when the pilot leans one way or another, so do the rotors.
On Thursday, the Canadian team, including pilot Todd Reichert, received the prize money from the American Helicopter Society and Sikorsky, effectively rubber stamping AeroVelo's achievement. In 2009, Sikorsky increased the prize money to the current amount from the $10,000 set when the prize was established 33 years ago.
You can see a video of the winning flight below.