The prize for human-powered helicopter (HPH) flight may have been won – but we don’t know for sure yet. University of Maryland’s (UMD) Gamera team completed flying on June 26, but did not qualify for the $250,000 Sikorsky Prize, administered by the American Helicopter Society (AHS) International. Meanwhile, Canada’s AeroVelo team is waiting for AHS to rule whether a June 14 flight by its Atlas quadrotor has won the prize.
AeroVelo Atlas (Photo: AHS International)
To win, the helicopter must fly on human power for 60 seconds, reaching 3 meters altitude while remaining within a 10-meter square. AeroVelo says the Atlas flew to 3.3 meters, stayed aloft for 65 seconds and drifted no more than 10 meters. AHS’s HPH committee is reviewing the team’s data package and will decide in a week or so.
UMD met all the duration, altitude and control requirements for the prize – but not on the same flight. On one flight, the improved Gamera IID reached 3.3 meters, but flew for 48 seconds. On another, the aircraft flew for 74 seconds and drifted less than 10 meters, but didn’t make the altitude. On a third, the quadrotor flew for 60 seconds and reached 2.85 meters.
All of the teams have struggled to control the drift of a very large, but very light helicopter. AeroVelo has manual control via canard surfaces on the rotor blades. Gamera finally went with an electronic control system that varies rotor rpm by means of electric motors. All electric power is generated by the pilot during flight and the system is controlled via switches on the hand grips. Spotters relayed commands to the pilot coach at the center of the vehicle, who then relayed the commands to the pilot.
Gamera IID (Photo: UMD Gamera Team)
Once it had cracked the control problem, the Gamera team struggled to reach the required altitude because the quadrotor had put on weight over time from additions and repairs to the ultralight carbonfiber structure. The aircraft was put on a diet and, as the June 26 flights show, the improved Gamera IID emerged capable of beating the altitude requirement. But Atlas had already shown it could get to 3 meters quicker than expected, and with some tweaks to the rotor trimming and some weight reductions of offset repairs looked well set to take the prize.