Instrument Errors / Compass

Magnetic compass errors and related effects: Variation, Deviation, Magnetic dip, Acceleration/deceleration error, Northerly turning error. Commonly taught alongside ANDS (Accelerate North, Decelerate South) and UNOS (Undershoot North, Overshoot South).

Source FAA Pilot’s Handbook of Aeronautical Knowledge (FAA-H-8083-25) · checked 2026-08-25