直升机飞行中旋翼打尾梁的起因和预防

中心铰式旋翼不产生桨毂力矩,当这类直升机由于急推杆或减小桨距而进入失重状态时,会丧失横向操纵功效及角速度阻尼。如果操纵失当,直升机会陷入急剧横滚并导致旋翼浆叶冲撞挥舞下限动器,造成旋翼破坏以及砍打尾梁、空中解体的灾难。为避免这类事故应防止进入低g或失重状态,保持足够的操纵功效。万一进入失重并发生自发的横滚,必须首先向后拉杆以改出失重状态,待恢复操纵功效后才可施加横向操纵以纠正横滚。

THE ANALYSIS AND PREVENTION OF ROTOR-TAIL COLLIDING DISASTER

No hub moment on a centric articulated rotor makes this kind of helicopter losing the control power and rate damping in weightless flight status,An improper control action,such as pushing the stick or lowering the collective over-quickly,can lead to a rapid rolling and the blade will hit the droop stop (Mast Bumping) ,resulting in rotor damage,or even makes the blade hitting the tail boom,so that the helicopter disintegrated in the air.To avoid this type of accident ,the pilot should not enter the low-g or weightless flight status ,and keep enough control power in his hand.If he was encountering these bad situations,he should pull back the cyclic stick for escaping from the weightless status first before he does any other control action.