单发直升机H-V飞行包线理论分析

Theoretical Analysis of H-V Flight Envelope of Single Engine Helicopter

直升机H-V(高度-速度)飞行包线是直升机在发动机失效后安全着陆或成功复飞的基础条件。在试飞确定直升机H-V飞行包线前,需要进行理论分析,确定飞行包线随飞行速度、高度的变化。本文基于H-V飞行包线理论,并结合笔者实际飞行经验,分析了某型单发直升机H-V飞行包线随飞机质量、飞行速度、着陆条件、旋翼转速的变化趋势。当单发直升机飞行中如遇发动机停车时,飞行人员能够结合直升机高度、速度、旋翼转速信息及时进入自转并规避不安全飞行范围。同时为飞行人员进行单发直升机模拟自转试验提供了理论基础。

H-V flight envelope is the basic condition for helicopter to land safely or go around successfully after engine failure.Before determining the H-V flight envelope of helicopter in flight test,theoretical analysis is needed to determine the change of flight envelope with flight speed and altitude.Based on the H-V flight envelope theory and combined with actual flight experience,this paper analyzes the variation trend of H-V flight envelope of a single engine helicopter with aircraft mass,flight speed,landing conditions and rotor speed.When the engine stops in the flight of single engine helicopter,the pilots can timely enter the autorotation and avoid the unsafe flight range based on the helicopter height,speed and rotor speed information.At the same time,it provides a theoretical basis for pilots to carry out single engine helicopter simulation rotation test.