时间：2011-03-11 23:11来源：蓝天飞行翻译 作者：admin 点击：次
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advanced timing (reciprocating engine ignition timing). Timing of the ignition of the fuel-air mixture in the cylinders of a reciprocating engine, so the mixture is completely burned by the time the piston reaches the top of its stroke. Advanced timing allows the maximum pressure to be produced in the cylinder as the piston starts downward. advancing blade (helicopter rotor blade). The blade in a helicopter rotor system moving in the same direction the helicopter is traveling. advection. A method of heat transfer by horizontal movement of a fluid. Advection is different from convection in that convection transfers heat by vertical, rather than horizontal, movement of the fluid. advection currents (meteorology). Currents of air moving horizontally over a surface. advection fog (meteorology). Fog that forms when moist air moves horizontally across a surface cold enough to cool the air to a temperature below its dew point. Moisture condenses and remains suspended in the air to obstruct visibility. adverse yaw (flight operation). A flight condition at the beginning of a turn in which the nose of an airplane starts to move in the direction opposite the direction the turn is being made. Adverse yaw is caused by the induced drag produced by the downward-deflected aileron holding back the wing as it begins to rise. “Advise intentions” (air traffic control). A request meaning “Tell me what you plan to do.” Advisory Circular. See AC. Advisory Service. Advice and information provided by an FAA facility to assist pilots in the safe conduct of flight and aircraft movement. aeration. The process of mixing air in a liquid. When lubricating oil passes through an engine, it picks up a good deal of air and is said to be aerated. This air must be removed by a process called deaeration. aerial (aeronautical). A term having to do with the air or with aircraft. It is used in such terms as aerial photography, aerial mapping, or aerial refueling. aerial (radio communications). A term used for a radio antenna. aerial photography. The business of taking pictures from aircraft in flight. There are two basic types of aerial photography: oblique and vertical. Vertical photography is used for mapping. In this process, the aircraft is flown at a high altitude, and special cameras take pictures of the terrain directly below the aircraft. Oblique photography, in which hand-held cameras are used to take pictures of objects on the ground, is used for news photography and advertising. Doors or windows are usually removed from the aircraft used for oblique aerial photography. aerial refueling. A method used to extend the range of military aircraft by refueling them in the air. Flying tankers rendezvous (meet) with the aircraft to be refueled, and large amounts of fuel are transferred in flight. Aerodrome. The name given by Dr. Samuel P. Langley to the flying machines built under his supervision between the years of 1891 and 1903. |
