Development of the autogyro continued in the search for a means to accelerate the rotor before takeoff (called prerotating). Rotor drives initially took the form of a rope wrapped around the rotor axle and then pulled by a team of men to accelerate the rotorthis was followed by a long taxi to bring the rotor up to speed sufficient for takeoff. The next innovation was flaps on the tail to redirect the propeller slipstream into the rotor while on the ground. This design was first tested on a C.19 in 1929. Efforts in 1930 had shown that the development of a light and efficient mechanical transmission was not a trivial undertaking. In 1932 the Pitcairn-Cierva Autogiro Company of Willow Grove, Pennsylvania, United States solved this problem with a transmission driven by the engine.
Development of the autogyro continued in the search for a means to accelerate the rotor before takeoff (called prerotating) Rotor drives initially took the form of a rope wrapped around the rotor axle and then pulled by a team of men to accelerate the rotorthis was followed by a long taxi to bring the rotor up to speed sufficient for takeoff The next innovation was flaps on the tail to redirect the propeller slipstream into the rotor while on the ground This design was first tested on a C19 in 1929 Efforts in 1930 had shown that the development of a light and efficient mechanical transmission was not a trivial undertaking In 1932 the Pitcairn-Cierva Autogiro Company of Willow Grove Pennsylvania United States solved this problem with a transmission driven by the engine