Enroute Map Practice Test

Magnetic variation is the angular difference between true north and magnetic north at a given location, and it’s the tool pilots use to translate between true and magnetic information. In enroute navigation you’ll rely on true courses on planning charts, but your instruments and many navigation aids are based on magnetic headings. By applying the variation, you convert a true course into the magnetic course you should fly, or reverse a magnetic course to determine the true heading you’ll track. For example, if the true course is 060° and variation is 8° East, the magnetic course is 068°; conversely, a magnetic course of 068° corresponds to a true course of 060°. Variation changes with location and over time, so current variation values must be used to maintain accurate routing. This concept is essential for maintaining the intended track, whereas VOR frequencies or published altitudes aren’t affected by variation.