True heading

True heading is the direction an aircraft's nose points measured clockwise from true north. It is a geographic reference. True heading differs from magnetic heading because of magnetic variation, and the compass indication can differ further because of aircraft deviation.

How it works

A true heading is referenced to the geographic meridians that point toward true north. A magnetic heading is referenced to the local direction of the earth's magnetic field. Pilots convert between true and magnetic values using the variation published on the applicable chart or navigation source.

Heading describes where the nose points, not necessarily where the aircraft travels. Wind can push the aircraft sideways, so the aircraft may hold a crab angle with a true heading different from its true track. A bearing also answers a different question because it points from one location toward another.

Example

An aircraft's true heading is 090°, meaning the nose points toward true east. If the local variation is 12° east, the equivalent magnetic heading will differ according to the stated convention. The pilot uses the chart and aircraft procedure to make the conversion rather than applying a memorized rule without checking the reference.

Why it matters

Mixing true and magnetic references can create course errors, especially when working from a charted true course and entering a magnetic heading into an instrument. The source of every direction should be clear before a calculation or cockpit entry.

Use current chart data and the aircraft's approved navigation equipment. This entry explains terminology and does not replace a flight plan, navigation log, or current procedure.

Related terms and tools

• Magnetic variation
• Bearing
• Track