A Case of Longitudinal Stick-Free Dynamic Instability of an Aircraft Fitted With Power-Operated Control, g-Restrictor and Spring Feel

摘要

The main findings of the investigation, which are given in the Introduction and fully set out in the discussion and conclusions at the end of the paper, can be summarized briefly as follows:n(a) With such a control system, instability of the aircraft short-period oscillatory mode can result. In these circumstances damping of this oscillatory mode deteriorates progressively with increase of speed.n(b) Friction in the control circuit is an important factor affecting the characteristics of the aircraft stability.n(c) It is considered that by care in design, particularly as regards positioning of the bob-weight, and choice of gearing, such instability can be avoided. Each case, however, requires examination on its own merits, on the lines of the analysis given here.