Definition
In aviation usage, 'magnetic' indicates that a direction, heading, course, or bearing is referenced to magnetic north — the direction a magnetic compass needle points — rather than to true north (the geographic North Pole) or grid north. Headings and courses on charts and in clearances are typically given in magnetic degrees unless otherwise stated.
Plain English
It means the direction is measured from where a compass points, not from the actual top of the Earth.
Context Anchor
Seen in FAA abbreviations, NOTAMs, charts, runway information, and navigation text when a direction is being described.
Derivation
From the Latin 'magneticus,' relating to a magnet. The term reminds the pilot that the reference is the Earth's magnetic field, which a compass responds to — not the geographic pole.
Why Pilots Care
Compasses and most cockpit instruments reference magnetic north; using MAG values keeps navigation consistent with what the instruments actually display.
Intuition Check
Magnetic does not usually mean “able to stick to metal” in this aviation context. Here it means “referenced to magnetic north.”
Example Sentence 1
ATC instructed the pilot to turn right to a heading of 090 magnetic.
Example Sentence 2
The sectional chart shows the VOR radial as 045 MAG, matching the compass reading the pilot will fly.