Note on the dynamic characteristics of servo-tab systems of control

Abstract

Generalised curves have been constructed from which estimates can be made of those dynamic characteristics of the servo-tab-type of control which are of chief interest to the designer, viz., (i) the magnitude of the first overshoot of the main flying control beyond its equilibrium position, (ii) the lag of the main control surface behind the tab movement, (iii) the damping of the main control surface oscillation, (iv) the angular velocity possessed by the main control when it first passes through its equilibrium position. The characteristics evaluated for two specific cases, a 50,000-1b and a 300,000-1b aircraft, indicate no special problems to the designer or pilot except with regard to overshoot of the control at low flying speeds. Elastic stops are considered to be the most promising solution to this.