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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fan blade shingling (turbofan engine damage). A type of damage in which the midspan shrouds on the fan blades overlap, shingle fashion, rather than touching with face-to-face contact. Fan blade shingling is caused by a sudden stoppage of the fan, or by an overspeed condition. fan-in (digital electronic circuit). The number of inputs connected to a single digital logic circuit. fan marker (electronic navigation equipment). A highly directional radio signal transmitted vertically upward from a transmitter located along a navigational radio range. The output of the fan marker is heard only when the aircraft is directly above the transmitter, and this allows the pilot to know his exact location. fan-out (digital electronic circuit). The number of parallel loads connected to a single logic circuit. fan pressure ratio (turbofan engine parameter). The ratio of the fan discharge pressure to the fan inlet pressure. FAP (final approach point) (air traffic control). The point, applicable only to a nonprecision approach with no depicted FAF (such as an on-airport VOR), where the aircraft is established inbound on the final approach course from the procedure turn, and where the final approach descent may be commenced. The final approach point serves as the final approach fix and identifies the beginning of the final approach segment. FAR (Federal Aviation Regulations). Regulations established by the Federal Aviation Administration which govern the operation of aircraft, airways, and airmen. Compliance with FARs is mandatory. In 1996, all references to the FARs were changed to “14 CFR” (Title 14 of the Code of Federal Regulations). farad (electrical unit). The basic unit of capacitance. One farad is the amount of capacitance that allows a charge of one coulomb to be stored under a pressure of one volt. The farad is too large for most practical circuits, so the microfarad (one millionth of a farad) and the picofarad (one millionth of a millionth of a farad) are the most generally used values of capacitance. Faraday’s law of electrolysis. The amount of any substance dissolved or deposited in electrolysis is proportional to the total electrical charge passed. Faraday’s law of electromagnetic induction. The electromotive force induced in a circuit by a changing magnetic field is determined by the rate of change of the magnetic flux linking the circuit. fast file (flight plan filing). A method of filing a flight plan by telephone. The flight plan is tape recorded and transcribed for transmission to the appropriate air traffic control facility. fatigue (metal condition). A condition existing in a metal which causes it to lose some of its strength. Fatigue occurs when the metal is subjected to a series of stress reversals, such as happens when the metal is repeatedly bent back and forth. fatigue crack (metal failure). A crack caused by stress reversals in a piece of metal. Vibration is one of the main sources of the stress reversals that cause fatigue cracks. |
