Pedal helicopter
A group of students and professors from California's polytechnic university have just done the feat few thought possible: launch a helicopter with human force.
The engineers believed that it was impossible to take off a helicopter only with human force. The power needed to fly the helicopter is much higher than the power needed to fly a plane. For example, a modern helicopter needs a horse to take off 4 kg. Under these conditions, the takeoff of a human being requires a power of 25-30 horses.
Fortunately, there is an easy way to reduce the necessary power: increase the rotor surface.
Californians have also used another trick: instead of acting directly on the clamping rotor, they do so by two small propellers placed at the ends (see figure).
Da Vinci III
The helicopter began to work in 1981. The rotor has a diameter of 30 m and a total weight of 45 kg. The first flights were made on 12 and 27 November at the gymnasium of the polytechnic university of California. The flights lasted two and four seconds respectively. The flight on December 10, the first official flight, controlled by the National Aeronautic Association, lasted 6.8 seconds. However, Da Vinci III cannot fly out, as the smallest wind would also unbalance it.
Da Vinci III
The Igor Sikorsky prize will not take place, but at least it will be the first step.
1.
This prize has $20,000 for the first helicopter launched with human force. However, it must reach an altitude of 3 m and a flight of 60 seconds and keep it within a square of 10 m of side.
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