$100,000 OFFERED FOR HELICOPTER AEROPLANE

A prize of $100,000 is offered by the Aero Club of France for the development of the "helicopter" type of machine which will be able to land and take off vertically, according to a recent announcement by the Aero Club of America. The prize is put up by Monsieur Michelin, long an ardent supporter of aviation.

This type of machine would be independent of horizontal flying speed to create pressure under its wings and would be able to land and to start from the roofs of buildings in the heart of a city. This implies the necessity of a motor strong enough to swing a propellor which would lift the machine by sheer strength without the help of the wings. It is in fact the application of the principle laid down by Orville Wright that a kitchen table could fly with sufficient engine power.

Various fast scout planes of high speed and unusual climbing ability have been said to approach a helicopter in their vertical climb but no one of these machines, no matter how powerful its engines, has been able to leave the ground at flying speed of less than 45 to 70 miles an hour. A large field is, of course, necessary for this type of plane, and in the aerial mail service for example an open expanse is often difficult to find.

Make "Back Yard" Machine Possible.

A number of experiments to this end have been carried on both in Europe and the United States with the idea of making the airplane independent of landing fields. If the attempt to produce the machine is successful, it would revolutionize the art of flying, and make possible the "back yard" machine which every man could own as he now owns his automobile.

Some of the difficulties in the way of developing the machine may be imagined by the conditions of the contest, which require that the airplane shall take the air vertically, have a range of speed up to 134 miles an hour, and land vertically within a radius of five metres.

Experiments in catapaulting the present type of machine, dependent for a start upon the swift passage of air over lift-creating planes, have increased the general interest in the possible development of the helicopter. In these experiments the machine is shot off a starting platform, much as a dart is thrown in the air. The start is so swift that the machine is able to pick up its flying speed and continue flight with its own engine.

Peter Cooper Hewitt and Francis Bacon Crocker have both experimented with the helicopter and obtained encouraging results. Scores of patents have been issued for this type of craft and the inventors have been divided into two classes--those who try to lift the machine by vertical propellors and those who attempt it with rotating wings.