时间：2011-03-11 23:13来源：蓝天飞行翻译 作者：admin 点击：次
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idler gear (gear train). A gear used to reverse the direction of rotation of another gear without changing its speed of rotation. An idler gear does not add nor take away mechanical advantage from the gear train. idler pulley (belt-drive system). A pulley in a belt-drive system used to adjust the tension on the belt that joins a drive pulley with a driven pulley. The idler pulley does not change the direction of rotation of either pulley, nor does it change the speed relationship between the pulleys. idle speed. The lowest speed at which an engine operates smoothly when it is not carrying any type of mechanical load. Idle speed is measured in revolutions per minute (RPM). idle thrust (gas turbine engine). The thrust produced by an aircraft gas turbine engine when the power control lever is pulled back to the idle stop. 14 CFR Part 1: “The jet thrust obtained with the engine power control lever set at the stop for the least thrust position at which it can be placed.” idling current (electronic equipment). Current flowing in an electronic circuit when there is no input signal requiring the system to act. Idling current, also called quiescent current, is normally much less than the operating current of the system. IFF (identification, friend or foe). An electronic identification system that is the forerunner of the modern radar beacon transponder used by air traffic controllers to identify specific aircraft. IFF, developed in the latter part of World War II, is an electronic pulse system in which interrogation pulses of electrical energy are transmitted from a ground station and received in the aircraft. If the airborne equipment is set to respond with the proper code, the IFF identifies the aircraft as friendly. But if the equipment does not reply with the correct code, the ground station is alerted to the fact that the indications received on its radarscope may be caused by a foe, or enemy. The principles of IFF equipment apply to other pulse navigation systems, especially aircraft radar beacon transponders and distance measuring equipment (DME). IFIM (International Flight Information Manual). A publication designed primarily as a pilot’s preflight planning guide for flights into foreign airspace and for flights returning to the U.S. from foreign locations. “If no transmission received for [time]” (air traffic control). A phrase used by ATC in radar approaches to prefix procedures which should be followed by the pilot in event of lost communications. IFR (instrument flight rules). Rules and regulations established by the Federal Aviation Administration to govern flight under conditions in which flight by outside visual reference is not safe. Instrument flight rules govern the flight of aircraft along the federally controlled airways and airports, and this flight is directed and controlled by operators on the ground. Flight according to instrument flight rules depends upon flying by reference to instruments in the cockpit, and navigation is done by reference to electronic signals. |
