The Direct Reading Compass is a crucial instrument used in navigation to determine the direction of an aircraft and operates based on the principles of magnetism. It provides the Pilots with direct information regarding the heading, assisting to a more accurate navigation and maintain the desired course.

In using the magnetic compass for navigation purposes, there are more considerations than just the turning errors. The magnetic compass displays several errors in its use due to the following:

• Earth has a geographic (true) North Pole and a geographic (true) South Pole. A magnetic field exists around the earth, produced by the equivalent of a very large bar magnet within the Earth. This results in a magnetic North Pole and a magnetic South Pole and the direct magnetic compass indicates the Magnetic North.
• When the bar magnet or magnetic compass is acted on by a magnetic field other than the Earth's, such as the airctaft's magnetic field, the magnet deviates. Most metal objects or electrical fields produce a magnetic field that will cause the compass to read incorrectly. So, a direct reading compass on board affected now by both Earth's and aircraft's magnetic field will indicate the Compass North.