时间：2011-03-11 23:18来源：蓝天飞行翻译 作者：航空 点击：次
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TCDS replaces Aircraft Specifications which were issued to aircraft and components certificated under the CARs (Civil Air Regulations), the forerunner of the FARs, or 14 CFRs. typhoon (meteorology). A tropical cyclone in the eastern hemisphere with winds in excess of 65 knots. Ty-Rap. Patented nylon straps used to tie bundles of wire together. The Ty-Rap is wrapped around the wire bundle, and its toothed strap is passed through a loop having matching teeth. A special tool pulls the strap tight around the bundle, and as it is pulled, the teeth on the strap and the loop mesh and lock the loop in place. Once a Ty-Rap is pulled tight, it must be cut to remove it. U U-bolt. A U-shaped rod threaded on both ends. U-bolts are used to fasten round rods or pipes to a flat surface. UDF engine (Unducted Fan). The trade name registered by General Electric for type of ultra-high-bypass turbofan engine that drives one or more propellers which have between 8 and 12 blades. These blades, which are not enclosed in a duct or shroud, are very thin, have wide chords, and are highly swept back with a scimitar shape. An Unducted Fan engine can power airplanes flying at speeds of near Mach 0.8. UHB engine (ultrahigh-bypass). A gas turbine engine in which a fan, either ducted or unducted, has a bypass ratio greater than 30:1. UHF (ultrahigh frequencies) (radio frequencies). Frequencies of electromagnetic radiation between 300 and 3,000 megahertz. The wavelengths for ultrahigh frequencies range between 100 and 10 centimeters. The UHF band is between the VHF (very-high-frequency) and the SHF (super-high-frequency) bands. ultimate load (aircraft structural specification). The amount of load that can be applied to an aircraft structure before it fails. The limit load is the maximum load a structure is designed to carry, and the factor of safety is the percentage of limit load the structure can actually carry before its ultimate load is reached. A structure designed to carry a load of 1,000 pounds with a safety factor of 1.5 has an ultimate load of 1,500 pounds. ultimate tensile strength. The tensile stress required to cause a material to break or to continue to deform under a decreasing load. ultrahigh frequencies. See UHF. ultralight vehicle. An aeronautical vehicle operated under 14 CFR Part 103 for sport or recreational purposes which does not require FAA registration, an airworthiness certificate, nor pilot certification. Ultralights are primarily single-occupant vehicles, although some two-place vehicles are authorized for training purposes. Operation of an ultralight vehicle in certain airspace requires authorization from ATC. ultrasonic cleaning. A method of cleaning mechanical components by vibrating them at an ultrasonic frequency while soaking them in a cleaning solution. ultrasonic frequencies. Frequencies of vibration higher than the human ear can hear. Ultrasonic frequencies are normally considered to begin at 20,000 hertz. |
