机务专业英语翻译

1.

The fuel system is designed to provide an uninterrupted flow of clean fuel from the fuel tanks to the engine. The fuel must be available to the engine under all conditions of engine power, altitude, attitude, and during all approved flight maneuvers. Two common classifications apply to fuel systems in small airplanes gravity-feed and fuel-pump systems.

The gravity-feed system utilizes the force of gravity to transfer the fuel from the tanks to the engine，for example, on high-wing airplanes where the fuel tanks are installed in the wings. This places the fuel tanks above the carburetor, and the fuel is gravity fed through the system and into the carburetor. If the design of the airplane is such that gravity cannot be used to transfer fuel, fuel pumps are installed，for example, on low-wing airplanes where the fuel tanks in the wings are located below the carburetor.

燃油系统是设计用来提供持续的从油箱到发动机的洁净燃油流量。燃油在所有发动机功率，高度，姿态和所有核准的飞行机动条件下必须能够供给发动机。小飞机上使用了两个常规类别的燃油系统-重力馈送系统和燃油泵系统。

重力馈送系统使用重力来把燃油从邮箱输送到发动机，例如，在上翼飞机上，油箱是安装在机翼里的。油箱被置于汽化器之上，燃油由于重力经过系统送到汽化器。如果飞机的设计不能用重力输送燃油，就要安装油泵，例如，在下翼飞机上机翼中的邮箱处于汽化器下方。

2.

FUEL PRIMER

Both gravity fed and pump systems may incorporate a fuel primer into the system. The primer is used to draw fuel from the tanks to vaporize it directly into the cylinders prior to starting the engine. This is particularly helpful during cold weather, when engines are hard to start because there is not enough heat available to vaporize the fuel in the carburetor. It is important to lock the primer in place when it is not in use. If the knob is free to move, it may vibrate out during flight and can cause an excessively rich mixture.

起动注油器

重力馈送和油泵系统也可以结合气动注油器。启动注油器用于气动发动机之前从油箱中抽油直接气化送入气缸。在冷天气特别有用，那时发动机会很难气动，因为没有足够的热量来气化汽化器中的燃油。气动注油器在不使用时锁定位置很重要。如果旋钮可以自由活动，飞行中它会被振动出来，引起过分富油。

3.

Wind shear is a sudden, drastic change in wind speed and/or direction over a very small area. Wind shear can subject an aircraft to violent updrafts and downdrafts as well as abrupt changes to the horizontal movement of the aircraft. While wind shear can occur at any altitude, low-level wind shear is especially hazardous due to the proximity of an aircraft to the ground. Directional wind changes of 180°and speed changes of 50 knots or more are associated with low-level wind shear. Low-level wind shear is commonly associated with passing frontal systems, thunderstorms, and temperature inversions with strong upper level winds (greater than 25 knots).

Wind shear is dangerous to an aircraft for several reasons. The rapid changes in wind direction and velocity change the wind’s relation to the aircraft disrupting the normal flight