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

68 Global Positioning System (GPS) GPS is a satellite-based navigation system composed of a network of satellites placed into orbit by the United States Department of Defense (DOD). GPS was originally intended for military applications, but in the 1980s the government made the system available for civilian use. GPS works in all weather conditions, anywhere in the world, 24 hours a day. A GPS receiver must be locked onto the signal of at least three satellites to calculate a two-dimensional position (latitude and longitude) and track movement. With four or more satellites in view, the receiver can determine the user’s three-dimensional position (latitude, longitude, and altitude). *https://www.waybuilder.net/free-ed/Resources/15-Transportation/Aviation/ AircraftStructure.asp?iNum=4 (09.01.2020). LANDING GEAR Landing gear position is controlled by a switch in the cockpit. In most airplanes, the gear switch is shaped like a wheel to facilitate positive identification and to differentiate it from other cockpit controls. An electrical landing gear retraction system utilizes an electrically driven motor for gear operation. The system is basically an electrically driven jack for raising and lowering the gear. When a switch in the cockpit is moved to the UP position, the electric motor operates. If the switch is moved to the DOWN position, the motor reverses and the gear moves down and locks. The primary benefits of being able to retract the landing gear increase climb performance and higher cruise airspeeds due to the resulting decrease in drag. Retractable landing gear systems may be operated either hydraulically or electrically, or may employ a combination of the two systems. A landing gear safety switch, sometimes referred to as a ‘squat switch,’ is usually mounted in a bracket on one of the main gear shock struts. Because of their complexity, retractable landing gears demand a close inspection prior to every flight. The inspection should begin inside the cockpit. The pilot should first make certain that the landing gear selector switch is in the GEAR DOWN position. The pilot should then turn on the