Control-surface flutter with the stick free

Abstract

The determination of the stick-free flutter characteristics of a control system when the inertia of the stick is allowed for is considered. A method of solution is proposed which corresponds to impedance matching between circuit and control surface in the flutter condition. The method is applied, by way of illustration, to two typical cases, an elevator system and a servo-tab system, and the effect of variations in stick inertia and circuit stiffness demonstrated, Conclusions drawn from these two cases are listed separately, but it is concluded generally that stickfree flutter can occur in the absence of stick-fixed flutter, and that the stickqree flutter characteristics may be quite different from those for the circuit-cut condition.