CHAPTER 2 NAVIGATION

CHAPTER 2 NAVIGATION The term navigation is defined as the process of directing the movement of a craft from one point to another. Air navigation, unlike sea or naval navigation, involves movement above the surface of the earth. There are unique conditions encountered in air navigation that have a special impact on the navigator. . Need for continued motion. A ship can stop and resolve any uncertainty of motion or wait for more favorable conditions if necessary. Most aircraft must keep going. l Limited endurance. Most aircraft can remain aloft for relatively short periods of time, usually figured in hours. . Greater speed. Because of the high rate of speed, the navigation methods and procedures must be done quickly and accurately. . Effect of weather. Visibility affects the use of landmarks. The wind has a more direct effect on aircraft position than on ships or vehicles. Changes in atmospheric pressure and temperature affect the height measurement of aircraft using barometric altimeters. Some type of navigation has been used ever since humans started to venture away from their homes. Exactly how they managed to find their way will remain a matter of conjecture, but some of their methods are known. The Greeks used primitive charts and a crude form of dead reckoning. They used the Sun and the North Star to determine direction. The early explorers used the astrolabe (fig. 2-1). It was not until the early 1700’s that an accurate timepiece (chronometer) and the sextant were invented, which made accurate navigation possible, even when far from land. Figure 2-1.-The ancient astrolabe. 2-1