Certified Flight Instructor - Flight Instructor Airplane Practice Exam

What happens to a magnetic compass when flying on a south heading while accelerating?

1. Indicates a turn to the east

2. Indicates a temporary turn toward the south

3. Maintains a perfect heading

4. It shows a left turn momentarily

The correct answer is: Indicates a temporary turn toward the south

When flying on a south heading while accelerating, the magnetic compass experiences a phenomenon known as magnetic dip. As the aircraft accelerates, the compass card tends to lag behind due to inertia. This causes it to show a momentary turn toward the south, even though the aircraft is maintaining a true south heading. This is because the compass is influenced by the aircraft's motion and magnetic forces. The acceleration creates a discrepancy between the physical heading of the aircraft and the compass indication, resulting in what is perceived as a temporary turn. This is a common characteristic of magnetic compasses and is crucial for pilots to understand, as it can lead to navigation errors if not accounted for. The other choices do not accurately describe the behavior of the magnetic compass under these conditions. Options implying stable or opposite directional indications do not reflect the actual compass behavior during acceleration on a south heading.