Published online by Cambridge University Press: 28 July 2016
The primary purpose of this note is to draw attention to the powerful influence of Coriolis forces and flapping pin offset on helicopter stability. It is shown that, for a conventional rotor of small offset, the damping in pitch and the flight stability are greatly reduced by the absence of drag hinges, an effect which may explain the use of stabilising bars on the successful helicopters which use this configuration. A “see-saw” rotor without some form of synthetic damping would be very unpleasant to fly by present-day standards.