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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class-B amplifier (electronic amplifier). An electronic amplifier whose output current flows only during one half of the input cycle. Two class-B amplifiers can be connected in such a way that each amplifies one half of the input signal. Both amplifiers are connected to a single output device. Class-B amplifiers are called push-pull amplifiers. Class B fire. A fire that has combustible liquids as its fuel. Class C airspace. Generally, that airspace from the surface to 4,000 feet above the airport elevation (charted in MSL) surrounding those airports that have an operational control tower, are serviced by radar approach control, and that have a certain number of IFR operations or passenger emplanements. Although the configuration of each Class C airspace area is individually tailored, the airspace usually consists of a 5 NM radius core surface area that extends from the surface up to 4,000 feet above the airport elevation, and a 10 NM radius shelf area that extends from 1,200 feet to 4,000 feet above the airport elevation. class-C amplifier (electronic amplifier). An electronic amplifier whose output current flows only during a small portion of one half of the input cycle. Class-C amplifiers are used to sustain radio-frequency oscillators by supplying pulses of energy to replace the energy lost in the resistance in the circuit. Class C fire. A fire which involves energized electrical equipment. Class D airspace. Generally, that airspace from the surface to 2,500 feet above the airport elevation (charted in MSL) surrounding those airports that have an operational control tower. The configuration of each Class D airspace area is individually tailored, and when instrument procedures are published, the airspace will normally be designed to contain the procedures. Class D fire. A fire in which a metal such as magnesium burns. Class E airspace. Generally, if the airspace is not Class A, Class B, Class C, or Class D, and it is controlled airspace, it is Class E airspace. Class G airspace. Generally that airspace that is uncontrolled, and has not been designated as Class A, Class B, Class C, Class D, or Class E airspace. class of thread (threaded fastener condition). A method of classifying the fit of threads used in bolts and nuts. A class-1 fit is a loose fit, a class-2 fit is a free fit, a class-3 fit is a medium fit, a class-4 fit is a close fit, and a class-5 fit is a wrench fit. Most fasteners used in aircraft structure have a class-3 fit. claw hammer. A hammer used for driving and removing nails from wood. The claws which are used to remove nails may be either straight or curved. clean room. A special room used for manufacturing and servicing precision equipment. The air in a clean room is filtered, and special precautions are taken to prevent dust, dirt, or other contamination entering the room. The workers wear special clothing to prevent contamination from their street clothes or from their hair. clear air turbulence. See CAT. |
