What is the purpose of using a magnetic compass in navigation?

The purpose of using a magnetic compass in navigation is primarily to determine the heading and direction of the aircraft. The magnetic compass works by aligning itself with the Earth's magnetic field, providing pilots with a straightforward and reliable means of navigating by offering a visual indication of the aircraft's orientation relative to magnetic north. This is crucial for maintaining a desired flight path, especially in situations where visual references are limited, such as over water or in poor weather conditions.

In aviation, knowing the heading allows pilots to adjust their course as needed and make necessary navigational decisions. It assists in situational awareness, enabling pilots to compare their heading against waypoints or navigational aids.

The other options serve different purposes in aviation, such as calibrating instruments like the altimeter, calculating fuel consumption, or measuring wind speed, but they do not relate directly to the fundamental navigation function of the magnetic compass.