Definition
A magnetic compass that has been stabilized using a gyroscope to reduce the swinging, lag, and acceleration errors of an ordinary magnetic compass. The gyro holds the compass card steady so that heading information remains accurate during turns, climbs, descents, and changes in airspeed.
Plain English
A magnetic compass that uses a small spinning wheel inside it to keep the heading display steady, so the numbers don't swing around when you turn or change speed.
Context Anchor
Seen in radar approach discussions, where ATC may give the pilot headings to fly during an ASR or PAR approach.
Derivation
Stabilized comes from Latin stabilis meaning 'steady' or 'firm.' A plain magnetic compass is anything but steady in flight — it bobs and lags. Adding a gyroscope makes the reading firm and reliable, hence 'stabilized.'
Why Pilots Care
Provides reliable heading information needed to intercept the final approach course accurately and avoid overshooting or undershooting the desired track.
Grounding Statement
Picture flying in cloud while ATC says, “Turn right heading two seven zero”; a stabilized compass is the steady heading reference you use to make that turn and hold it.
Intuition Check
Do not read “stabilized compass” as just any ordinary magnetic compass. Here it means a heading reference steady enough to use for instrument flying and radar vectors.
Example Sentence 1
The heading shown on the HSI comes from the stabilized compass system, not directly from the standby magnetic compass on the windshield.
Example Sentence 2
The approach controller delayed the next heading instruction until the aircraft was flying a stabilized compass.