When decelerating while heading south, what compass error occurs?

When an aircraft is decelerating while heading south, the compass will typically show a turn to the north. This phenomenon is known as compass position error, specifically caused by the acceleration and deceleration of the aircraft.

As the aircraft slows down, the magnetic compass tends to lag due to its design, which can cause the compass card not to reflect the actual heading immediately. Instead, it may momentarily indicate a turn to the north, even though the aircraft is maintaining a southerly heading. This is a key concept in understanding compass behavior and navigation in aviation.

In this scenario, the compass's behavior is influenced by the inertia of the compass fluid and the magnetic forces acting on it. Therefore, it is essential for pilots to be aware of this error to interpret compass readings accurately during flight maneuvers.