During which scenario does the magnetic compass experience acceleration error?

The magnetic compass experiences acceleration error primarily when an aircraft accelerates while flying on an east-west heading. When an aircraft is flying southbound and experiences acceleration, the compass will indicate a turn towards the east due to the inertia of the compass card. This is because the compass relies on the Earth's magnetic field and the force of inertia affects how it responds to changes in speed.

In the specific case of accelerating from east to west, the magnetic compass will initially lag behind and indicate a turn to the north due to the complex interaction between inertia and the magnetic field. This leads to a false heading that the pilot must account for during flight.

Understanding this phenomenon is crucial for pilots, as it can lead to navigational errors if not recognized and corrected. Therefore, recognizing that the magnetic compass behaves in a particular way under acceleration—especially when turning during acceleration from east to west—is important for safe flying practices and maintaining proper situational awareness in navigation.