tailplane and both it and the fin carried small movable trimming surfaces. Each licensee used nationally built engines and used slightly different names. In all, 143 production C.30s were built, making it by far the most numerous pre-war autogyro. Between 1933 and 1936, de la Cierva used one C.30A (G-ACWF) to test his last contribution to autogyro development before his death in the crash of a KLM Douglas DC-2 airliner at Croydon Airfield in England on 9 December 1936. To enable the aircraft to take off without forward ground travel, he produced the "autodynamic" rotor head, which allowed the rotor to be spun up by the engine in the usual way but to higher than take-off r.p.m at zero rotor incidence and then to reach operational positive pitch suddenly enough to jump some 20 ft (6 m) upwards. At least one Royal Air Force (RAF) C.30A was on floats as a Sea Rota in January 1935. Production Avro Avro obtained the licence in 1934 and subsequently built 78 examples, under their model designation, fitted with an Armstrong Siddeley Genet Major IA (known in the RAF as the Civet 1) 7-cylinder radial engine producing . The first production C.30A was delivered in July 1934. Lioré-et-Olivier Twenty-five aircraft were built in France by Lioré-et-Olivier as the LeO C.301 with a 175 hp (130 kW) Salmson 9NE 9-cylinder radial engine. Focke-Wulf Forty aircraft were built in Germany as the Focke-Wulf Fw 30 Heuschrecke (Grasshopper) with a 140 hp (105 kW) Siemens Sh 14A 7-cylinder radial engine. Operational history Of the 66 non-RAF aircraft built in the UK by Avro, 37 appeared at least for a while on the UK register. Some (maybe a dozen) were sold abroad, but others were flown by wealthy enthusiasts and by flying clubs who offered autogyro training. By the end of the decade, private flyers were moving back to the comforts and economies of fixed-wing aircraft and more C.30s moved abroad leaving the Autogyro Flying Club at London Air Park, Hanworth as the major UK user. 26 aircraft were directly exported by Avro. These went both to private owners and to foreign air forces who wish to investigate the autogyro's potential. In 1934, one Spanish Navy C.30 piloted by Cierva landed on the Spanish Seaplane tender Dedalo anchored in Valencia harbor and later made a takeoff. In September 1935, five members of the Lithuanian Aero Club flew C.30A