時(shí)間：2011-03-11 23:11來源：藍(lán)天飛行翻譯 作者：admin 點(diǎn)擊：次
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active infrared detection. The method of detection in which a beam of infrared rays is transmitted toward a suspected target. Reflected rays from the target are used to detect and identify it. active runway (air traffic control). Any runway or runways currently being used for takeoff or landing. When multiple runways are used, they are all considered to be active runways. actuating cylinder (fluid power system component). A cylinder and piston arrangement used to convert hydraulic or pneumatic fluid pressure into work. Fluid under pressure moves the piston that does the work. actuating horns. Levers attached to aircraft control surfaces to which control cables are connected to move the surfaces. actuator (fluid power system component). A device which transforms fluid pressure into mechanical force. Actuators may be linear, rotary, or oscillating, and they may be actuated by either hydraulic or pneumatic pressure. ACU (acceleration control unit) (turbine engine fuel control). The section in a turbine engine fuel control that schedules the rate of increase of the fuel to the nozzles when the engine controls call for acceleration. The ACU prevents the engine from stalling during acceleration. acute angle. An angle of less than 90°. An acute angle is also called a closed angle. AD (airworthiness directive). A regulatory notice sent out by the FAA to the registered owner of an aircraft informing him or her of the discovery of a condition that prevents the aircraft from continuing to meet its conditions for airworthiness. Airworthiness directives, called AD notes, are covered by Title 14 of the Code of Federal Regulations Part 39 (Airworthiness Directives). They must be complied with within the specified time limit, and the fact of compliance, the date of compliance, and the method of compliance must be recorded in the aircraft maintenance records. adapter. An apparatus that modifies a device so some component can be attached to it. Adapters, for example, are used on the ends of air hoses to attach them to air drills and rivet guns. ADC (air data computer). An electronic computer in an aircraft that senses pitot pressure, static pressure, and total air temperature. It produces an indication of altitude, indicated airspeed, true airspeed, and Mach number. The output of the ADC is usable by any of the engine or flight control computers. Adcock antenna (radio antenna). A type of directional radio transmitting antenna made of two vertical conductors from which electromagnetic energy radiates. These conductors are connected in such a way that the signals radiated from them are opposite in phase. An Adcock antenna radiates its signal in a field shaped much like a figure eight. adder (electronic computer). An arrangement of logic gates in a computer that adds two bits (binary digits) and produces a sum and a carry bit. addition (mathematics). The process of computing with sets of numbers to find their sum. |
