Aviation Technical English for aircraft maintenance engineers (Авиационный технический английский язык для студентов-авитехников)

65 The propeller, mounted on the front of the engine, translates the rotating force of the engine into thrust, a forward acting force that helps move the airplane through the air. The propeller may also be mounted on the rear of the engine as in a pusher-type aircraft. A propeller is a rotating airfoil that produces thrust through aerodynamic action. A low pressure area is formed at the back of the propeller’s airfoil, and high pressure is produced at the face of the propeller, similar to the way lift is generated by an airfoil used as a lifting surface or wing. This pressure differential pulls air through the propeller, which in turn pulls the airplane forward. Propellers are usually matched to a specific aircraft/powerplant combination to achieve the best efficiency at a particular power setting, and they pull or push depending on how the engine is mounted. Subcomponents The subcomponents of an airplane include the airframe, electrical system, flight controls, and brakes. The airframe is the basic structure of an aircraft and is designed to withstand all aerodynamic forces, as well as the stresses imposed by the weight of the fuel, crew, and payload. The primary function of an aircraft electrical system is to generate, regulate, and distribute electrical power throughout the aircraft. There are several different power sources on aircraft to power the aircraft electrical systems. These power sources include: engine-driven alternating current (AC) generators, auxiliary power units (APUs), and external power. The aircraft’s electrical power system is used to operate the flight instruments, essential systems such as anti-icing, etc., and passenger services, such as cabin lighting. The flight controls are the devices and systems which govern the attitude of an aircraft and, as a result, the flightpath followed by the aircraft. In the case of many conventional airplanes, the primary flight controls utilize hinged, trailing-edge surfaces called elevators for pitch, ailerons for roll, and the rudder for yaw. These surfaces are operated by the pilot in the flight deck or by an automatic pilot. Airplane brakes consist of multiple pads (called caliper pads) that are hydraulically squeezed toward each other with a rotating disk (called a rotor) between them. The pads place pressure on the rotor which is turning