In Italy, Corridion D'Ascanio built a machine with two 13m counter-rotating coaxial rotors, each with a trailing elevator which could be used to vary the rotor blade angle of attack. Two small propellers at the ends of long arms were used for additional control. The propulsion/control system was powered by a 95hp Fiat engine. The vehicle set three Federation Aeronautique Internationale (FAI) world records on October 8, 1930: an altitude of 18m, a distance of 1078m, and endurance of 8 minutes and 45 seconds.
Building on Juan de la Cierva's invention of the autogiro and his many rotor patents, Europe had a commanding lead in helicopter development as the 1930s began. At the start of the decade, a coaxial helicopter built by d'Ascanio flew to a height of 18m in Italy.
J.P.Spencer "Whirlybirds: A History of the U.S. Helicopter Pioneers", 1998
Technical data for Ascanio
Engine: 1 x Fiat A-505 rated at 95-100hp, rotor diameter: 13-15m, take-off weight: 800kg, achieved height: 18m, achieved endurance: 8min 45s