Cierva C.40


The autogyro evolved from earlier models during this time. A Spaniard named Juana de la Cierva experimented with autogyros for the allies in Great Britain until his death in 1936 (Sadler 2). Two Cierva C.40 autogyros were used for Air Observation Post during World War I. They did have some setbacks, however. Autogyros could neither hover nor descend vertically like the modern helicopter. Relying on forward motion, the autogyros's primitive engine lacked the power to run as efficiently as the helicopters. The helicopter's superiority was made readily apparent by the planned replacement of the RAF's No. 529 Squadron's autogyros with the Sikorsky aircraft in 1944 (Sadler 2).