Evolution of Fighter Aircrafts in the interwar Years: Cluster Analysis in History of Engineering
The article carries out cluster analysis of piston-engine fighters designed between 1920 and 1944 and takes into account more than 500 modifications of aircrafts that were serially manufactured in 18 countries. The author divides the period understudy into five-year segments and studies designs as far as such parameters as maximum speed, wing load and power load are concerned. Correlations of these variables are considered as well and special attention is paid to the correct distance determination. The article demonstrates dynamics of the main fighter characteristics between the world wars. It was found out that the main factor in the growth of fighter speed in 1920-1944 was the wing load related to modernization of profiles, quality and mechanization of the wing rather than growth of engine power of aircrafts. One can see repeating models of development in each period. These are a “power” approach that used new technologies “straightforwardly”, for instance, by totally increasing power loading, and a complex approach that provided for much better results. The author has revealed the leadership of the British aerodynamic school in 1920-1940 and has numerically demonstrated the change in the focus of the US design school from a "powerful engine - light aircraft" method to a "perfect aerodynamics - long flight range" method. He has shown the place of the Soviet design school as well. It has been found out that the last (during this period) sharp increase of wing load was not performed in the USSR and Japan. This led to rather low speed of fighters in these countries during the Second World War. The author discusses the reasons for this as well.