Methods of navigation

Learning to fly occupied the minds of men almost from the beginning of recorded history. Legend tells of magic carpets and winged sandals. History brings us stories of flying machines, but man’s first powered flight in a heavier-than-air machine was made in 1903.

This flight lasted for 12 seconds and covered a distance over the ground of only 120 feet. This flight was made against wind of 24 mph and was equal to a flight of 540 feet in still air. The maximum altitude attained was 12 feet above the ground.

In the old days pilots listened to the winds in the wires and were happy to fly at any speed. But now a fast flying aircraft pushes through the atmosphere so rapidly that the air can't get out fast enough, because the air is compressed and heated by the compression. At such great speeds it's not so easy as before to pilot the plane, to determine the geographical position and to maintain desired directions to navigate.

Through centuries 4 principal methods of navigation have been developed. They may be briefly described as follows:

1. Pilotage, by which the pilot is directing the aircraft with the reference to visible landmarks.

2. Dead reckoning, by which the distance and direction are determined between two known positions, or in which position is determined from the distance and direction from a known position.

3. Radio navigation , or the determination of position by means of radio bearings, distances or time intervals.

4. Celestial navigation, in which position is determined by means of sextant observations of the sun, moon, planets, or stars, with exact time of the observations.

Navigator's role

Ever since the time when people found their way by using a column of smoke by day and fire by night, navigation, navigational techniques, and navigational aids have been the subject of discussion.

What is navigation? - Navigation is the art of determining the geographical position and maintaining desired direction of an aircraft relative to the earth's surface.

A navigator belongs to the flying staff of the crew. He performs his duties by means of navigational aids and different instruments installed along the airways as well as in a plane and by making numerous calculations. That's why a navigator must know technical aids of air navigation and methods of their application during flight perfectly well. He should make navigational preparations for flight in good time. The navigator's duties performed by him during flight, are rather numerous: he must navigate the plane according to the flight plan from take off to touch down; control the progress of the aircraft by means of all established navigational methods and technical aids. He must know and observe the rules of radio communication and keep watch on airborne aids. The navigator has to get flight charts prepared personally and in advance. In addition to all duties mentioned above he must make a correct estimate of the meteorological situation.

In the course of preliminary preparation of the crew for flight the navigator together with other members of the flying staff studies the order of conducting flight on a given airway and radio aids available. Navigator's task is to determine aircraft's position, direction and speed of flight.

Usually navigators fly on heavy planes. As aircraft become larger and faster, requirements to navigator's work increase. Longer flights sends out radio waves and then measures the amount of time that it takes for the waves to return.

A radar set includes a transmitter and a receiver. The transmitter sends out at regular intervals short pulses of high-frequency waves. These can penetrate clouds and darkness. They move out in a straight line. Having met some object they are reflected back to the radar set and are translated into a spot of light on the screen.

Ground radar is used to guide planes to a landing in bad weather.