HEREIN is presented for the first time a technical analysis of many of the fundamental engineering features of the development of the Autogiro by the engineering departments of the parent American company and its licensees. Intensive study is still being given to both the aerodynamic and the structural improvement of the rotor and also to other component elements. Attention is given in the paper to many of the developments that have contributed to the present engineering status of the machine in this Country.
Phases of the subject discussed and analyzed are the aerodynamic relationships existing in the three or four widely different combinations of rotor and fixed wing and the longitudinal balance and stability of these several types of Autogiro to determine the extent of displacement of the center of gravity that is possible without impairing the behavior of the machine in slow forward speed or nearly vertical descent, while still maintaining longitudinal stability at high speed.
The voluminous data presented show some of the engineering aspects of the latest craft and suggest the great volume of detail development work that has been involved in establishing the present standard of practice as regards the aerodynamic relationships of the rotor, fixed wing, tail surfaces and other elements.
Flight tests of pressure distribution on the fixed wings and further studies that are being conducted as to the influence of aspect ratio of the fixed wings on efficiency of the machine, of lift and thrust vectors on the rotor and of longitudinal balance and stability of new types developed, particularly with increase of gross load, promise the development of further improvements in efficiency, performance and utility.