Definition
A maintenance procedure in which an aircraft is taxied or rotated to a series of known magnetic headings on a compass rose so that the magnetic compass can be checked, adjusted, and any remaining errors recorded on a compass correction card. The procedure compensates for deviation caused by the aircraft's own electrical systems and metal structure.
Plain English
It's the process of pointing the airplane in several known directions on the ground, then checking what the compass actually reads in each direction. Small adjustments are made, and any leftover errors are written on a card in the cockpit so the pilot knows how much the compass is off when flying that heading.
Context Anchor
You will see this term in discussions of magnetic compass deviation, compass correction cards, and compass checks after maintenance or equipment changes.
Derivation
"Swinging" here means rotating the aircraft through a sequence of headings — the airplane is literally swung around to face north, east, south, west, and the points in between. The term comes from the physical act of turning the aircraft to each direction during the check.
Why Pilots Care
Produces the deviation card pilots use to correct compass headings, ensuring accurate navigation when other systems are unavailable.
Grounding Statement
The key idea is simple: point the airplane in known directions, read the compass, and note the error.
Intuition Check
Do not read “swinging the compass” as physically swinging or shaking the compass. In aviation, it means turning the aircraft through known headings to check and correct compass error.
Example Sentence 1
After installing the new avionics, the mechanic recommended swinging the compass to make sure the new wiring hadn't introduced extra deviation.
Example Sentence 2
Regulations require swinging the compass following any work that could alter the aircraft's magnetic characteristics.