What distinguishes magnetic variation from magnetic deviation?

The distinction between magnetic variation and magnetic deviation lies primarily in their sources and influences. Magnetic variation refers to the angle between true north (geographic north) and magnetic north as found on the Earth's surface. This variation is a result of the Earth's magnetic field and is influenced by geographical location. Pilots must take this into account when navigating to ensure accurate headings.

On the other hand, magnetic deviation occurs due to local magnetic fields within the aircraft itself, such as those produced by electrical equipment or metal components. This deviation can change based on the aircraft's orientation and electrical status, leading to inaccuracies in a magnetic compass reading.

This understanding of the differences is essential for pilots, as knowing how to compensate for both variation and deviation ensures more accurate navigation and safer flights.