Deviation


A magnetic compass error caused by local magnetic fields within the aircraft. Deviation error is different on each heading.

Source: Pilot's Handbook of Aeronautical Knowledge (definition from the FAA-H-8083-25B, 2016; current: FAA-H-8083-25C, 2023, with the October 2025 addendum).

Related terms

Glossary last updated 2026-10-28.