Historical Review of Two Helicopters Designed in the Netherlands

摘要

This paper gives a review of the two helicopters designed in the Netherlands. TheVon Baumhauer helicopter from the 1920's featured for the first time in history a single main rotor for lift, a tail rotor for countering the main rotor torque and collective and cyclic blade pitch for height, pitch and roll control of the helicopter. These principles had been patented in various European countries. It seemed that da la Cierva had adopted this rotor control principle for his autogiros, and from thereon it had been applied in almost all modern helicopters. Also the now commonly used main-rotor/tail-rotor concepts stems from von Baumhauer's patent. The 2-seat 'Kolibrie' (Hummingbird) from the 1950's was a tip-driven ramjet helicopter with a maximum all-up weight of 700kg. The helicopter featured a 9.95 m diameter 2-bladed main rotor and a 0.92 m diameter single bladed tail rotor. The machine application of this small helicopter was spraying and crop dusting. About 20 machines had been produced, of which about 12 ones have flown in 8 countries merely for agricultural purposes. The last one in Israel until in the 1980's with full satisfaction. Unfortunately, both projects ended due to financial reasons. In the Kolibrie case the sales were lacking far behind the expectations.