STUDENTS in California have pedalled into aviation history by successfully
flying a human-powered helicopter. The US National Aeronautic Association
(NAA) certified that the first official flight took place on 10 December,
when the helicopter lifted 8 inches (20 centimetres) off the ground for
The helicopter, known as the Da Vinci III, comprises two rotors spanning
30 metres with a cage slung beneath them. The pilot, who must weigh no more
than 59 kilograms, sits in the cage and pedals, driving two propellers placed
on the end of the rotors. The propellers move the rotors around to provide
lift. The whole machine weighs only 44 kg and is made from lightweight composites
and plastics. It is so light that it must be flown indoors, because the
slightest breeze would upset its balance.
About 25 undergraduates studying aeronautical engineering at the California
Polytechnic State University, San Luis Obisco, designed and built Da Vinci
III and its three predecessors, all of which failed. Neal Saiki, who is
the current project manager, says: ‘The earlier machines were huge, and
two of them tipped forward because the rotor blades weren’t quite straight.’
The students have spent the past six months redesigning Da Vinci III,
learning from their earlier failures. Extra guy wires under different tensions
now hold the rotors straight and the cage for the pilot is 9 kg lighter
than in the previous machines.
Da Vinci III lifted off for about two seconds on 12 November and again
on 27 November, but an NAA observer had to be present to set a record. The
NAA sent Thomas Stuelpnagel, a former president of Hughes Aircraft, now
McDonnell Douglas Helicopters, to certify the record attempt.
The students now want to design Da Vinci IV to try to win the Sikorsky
award of $20 000, offered by the American Helicopter Society for the first
human-powered helicopter that rises 3 metres for 60 seconds and stays within
a 10-metre square. Saiki says that the difficult part is designing the control
system to keep the craft within such a small area.
So far, companies such as McDonnell Douglas Helicopters and US Polymeric
have given about $100 000 worth of funding or materials to the students.
NASA’sAmes Research Center has allowed thestudents to design parts of the
machineon their supercomputer. Saiki says thatthe students now need about
$15 000 worthof materials and $10 000 cash for theirassault on the Sikorsky
prize. ‘If we getthe money within the next month or so,we could complete
Da Vinci IV by thesummer,’ he says.