Update: On Thursday, July 11, Team AeroVelo’s victory was announced. The winning flight was 64.11 seconds long. The Atlas reached an altitude of 3.3 meters. Follow-up to come. More information here:  http://www.aerovelo.com/2013/07/11/aerovelo-officially-awarded-ahs-sikorsky-prize/

AeroVelo, an engineering team led by U of T’s Dr. Todd Reichert and Cameron Robertson, is inches away from claiming the coveted Sikorsky prize, a challenge that has thwarted top university teams for over three decades. The challenge involves building a human-powered helicopter that can climb three meters and stay airborne for 60 seconds while remaining within a 10-meter square. The prize, awarded by the American Helicopter Society, comes with a $250,000 reward, making it the the third largest aviation prize in history.

Recent flight attempts conducted by  AeroVelo have come tantalizingly close to meeting the challenge’s strict requirements. On March 15, 2013, the team’s helicopter, Atlas, climbed within inches of three meters. However, within seconds, one of the rotors plummeted and the truss broke apart in mid-air. The team has quickly recovered from the crash and has repaired their helicopter with some adjustments. More tests will be conducted in June at the Vaughan Soccer Centre. Meanwhile, a helicopter built by a team from the University of Maryland has reached a height of 9.4 ft (2.9 meters) and has flown for over 60 seconds. The team will be conducting tests in late winter or early spring 2013.

The Atlas employs four giant rotors powered by a central bicycle. Measuring 49.4 metres in length and weighing only 121.4 lbs, the helicopter is also incredibly energy-efficient. This efficiency is in part due to computational modelling, which was used to optimize aerodynamic and structural properties, in conjunction with select building materials: a carbon fibre tube for the main spar and polystyrene foam for the airfoil.

Todd Reichert, team AeroVelo’s test pilot and chief structural engineer, is a national-level speed skater and competitive athlete of human-powered vehicles. He generates around 550 watts of average power to achieve the required altitude.

The concept of a human-powered helicopter is not a new idea. In fact, Leonardo Da Vinci conceived of a helicopter-like design called the Aerial Screw that was to be powered by four men turning cranks. Despite its innovative design, Da Vinci’s model was far too heavy to fly. The first “flyable” human powered helicopter was built more than four centuries after Da Vinci’s death by students at Cal Poly San Luis Obispo in 1989. The helicopter, aptly named the Da Vinci III, flew for only seven seconds, reaching a height of 20 centimeters. Since then, about 30 serious attempts at the Sikorsky prize have been made, with only a few helicopters ever achieving flight.

AeroVelo hopes that its team members’ creative thinking and determination will help it claim the Sikorsky Prize and inspire future generations of engineers. You can follow the team’s attempts through its website or on twitter.