时间:2011-03-11 23:13来源:蓝天飞行翻译 作者:admin 点击:次
hover check (helicopter operation). A stabilized hover of a helicopter or VTOL aircraft used to conduct a performance/power check prior to hover taxi, air taxi, or takeoff. hovering ceiling (helicopter flight). The maximum altitude at which a helicopter can support itself without forward motion. Hovering ceiling is normally given in two figures: in ground effect (IGE) and out of ground effect (OGE). hovering in ground effect (helicopter operation). A helicopter hovering in ground effect (IGE) is in flight, but it is not moving over the ground, and it is flying at a height equal to or less than the span of its rotor above the surface. A helicopter can hover in ground effect at a higher density altitude than it can hover out of ground effect. hovering out of ground effect (helicopter operation). A helicopter hovering out of ground effect (OGE) is in flight, but it is not moving over the ground, and it is flying at a height above the ground greater than the span of its rotor. hover taxi (helicopter operation). Movement of a helicopter or VTOL aircraft above the surface and in ground effect, at airspeeds of less than approximately 20 knots. HRD fire extinguisher (high-rate-discharge). A fire extinguisher that carries the extinguishing agent in a sealed sphere or cylinder. When the agent-discharged switch is closed, a powder charge drives a cutter through a frangible disk and releases the agent. The entire contents of the container is emptied in much less than a second. HSI (horizontal situation indicator). An electronic flight and navigation instrument that shows the pilot the proper changes to make in directional flight. An HSI shows the pilot the relationship of he aircraft to the VOR radial or ADF bearing, the magnetic direction, the desired course and heading, and also the relationship of the aircraft to the glide slope. hub of a propeller. The portion of a propeller that attaches to the propeller shaft of the engine. The propeller blades fasten into the hub. |