On a turn from the south, how does the compass react?

When making a turn from the south, the compass exhibits a behavior known as compass turn error, specifically a tendency to exaggerate the rate of turn when turning towards the east or west. This phenomenon occurs due to the magnetic variation and the way the compass operates with respect to the Earth's magnetic field.

During a turn from a southerly heading towards either an easterly or westerly heading, the compass may momentarily point in the direction of the new heading before actually being aligned with the aircraft's true heading. This gives the impression that the aircraft is turning faster than it really is. The compass will show a more significant change in heading than the actual change, which can lead to a misinterpretation of the aircraft's orientation during the maneuver.

Understanding this behavior is crucial for pilots, as it emphasizes the need for additional cues and instruments to accurately determine the aircraft's position during turns, especially those from cardinal headings. This awareness helps pilots make more informed decisions while maneuvering.