Definition
The direction the magnetic compass needle actually points in the aircraft, after being affected by the aircraft's own magnetic fields (deviation) in addition to the Earth's magnetic field. It differs from both True North and Magnetic North.
Plain English
The direction your aircraft's compass shows as north — which isn't quite the same as the real magnetic north, because metal and electrical equipment in the airplane pull the needle slightly off.
Context Anchor
Used in navigation and heading correction when working with a magnetic compass, compass correction card, or heading calculations.
Derivation
From the magnetic compass instrument itself. 'Compass North' literally means 'north as the compass shows it' — emphasising that the reading belongs to that specific instrument in that specific airplane, not to the Earth.
Why Pilots Care
Prevents heading errors that could lead to navigation mistakes or unsafe flight paths.
Intuition Check
Compass North does not mean geographic north. It means the north direction shown by the aircraft’s compass, including any error from that compass installation.
Example Sentence 1
After applying deviation from the correction card, the pilot turned to a Compass North heading and began the cross-country leg.
Example Sentence 2
After the compass swing, the mechanic recorded the new compass north error card for the aircraft.