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.