Evaluation of Iroquois UH-1B Stability and Control

摘要

The purpose of this investigation was to evaluate the forward flying qualities of the Iroquois UH-1B helicopter for the Training and SAR missions as conducted by the Royal Australian Air Force. Several unsatisfactory handlng characteristics were identified. Highly undesirable features included the rapidly divergent longitudinal long term response in maximum power climbs; excessive vibration levels; coupling of sideslip to pitching moments; excessive trim changes when transitioning from climb to descent; and non-linearities in the collective fixed static longitudinal stability gradients in maximum power climbs. Undesirable features included the level flight gust response; longitudinal control response in level flight; lateral-directional oscillation; and adverse yaw. Posssible causes of the extremely divergent longitudinal long term response in high powered climbs and the sideslip-pitch coupling are discussed.