Which condition leads to a magnetic compass showing a turn towards the North when an aircraft is accelerated?

The condition that causes a magnetic compass to show a turn towards the North when an aircraft is accelerated occurs specifically when the aircraft is on a West heading. This phenomenon is primarily due to the magnetic dip and the inertia of the compass fluid.

When the aircraft is heading West and experiences acceleration, the compass will lag behind the actual heading. As the aircraft accelerates, the compass card tends to tilt because of the force applied to it, causing it to indicate a turn towards the North. This is known as "compass turning error" or "acceleration error." Pilots must be aware of this characteristic of the magnetic compass to make appropriate adjustments to their navigation and heading awareness.

In contrast, the compass would behave differently on other headings (North, East, and South), where the turning tendencies caused by acceleration do not lead towards North in the same manner as when on a West heading. This understanding is critical for accurate navigation, particularly when executing turns or adjusting for wind corrections.