时间:2011-03-11 23:18来源:蓝天飞行翻译 作者:航空 点击:次
sea level. The average level of the surface of the sea. Sea level is the mid position between the level of the water at low tide and the level at high tide. sea-level-boosted engine. A reciprocating engine that has had its sea-level rated horsepower increased by supercharging. This is the same as a ground-boosted engine. sea-level engine. 14 CFR Part 1: “A reciprocating aircraft engine having a rated takeoff power that is producible only at sea level.” sea-level pressure (meteorology). The atmospheric pressure that exists at mean (average) sea level. Sea-level pressure can be measured directly, by stations located at sea level, or determined from charts showing the station pressure and temperature taken at stations not at sea level. Sea-level pressure is used as a common reference for analysis of surface pressure patterns. seam welding (electrical resistance welding). A form of electrical resistance welding in which small metal wheels are used as the electrodes. These wheels roll over the metal, and the current is conducted through the metal from the wheel on one side to the wheel on the other side. Heat caused by the current flowing through the resistance of the metal softens the metal, and pressure between the wheels forces the softened metal in the two pieces to flow together. Seam welding is similar to spot welding, except that the weld is a continuous line, rather than individual spots. Fuel tanks are usually seam welded, rather than spot welded. seaplane. An airplane that can operate from water, rather than land. Some seaplanes are landplanes with the wheels removed and floats installed. A flying boat is a type of seaplane whose fuselage is similar to the hull of a boat. Sponsons (a type of stub wing near the water line) or wing-tip floats keep the flying boat relatively level while it is in the water. |