When experiencing a left turn from a North heading, how should the magnetic compass behave?

When an aircraft makes a left turn from a North heading, the magnetic compass has a specific behavior due to the principles of magnetic deviation and acceleration errors. When turning left toward the West, the compass correctly senses the turn and initially indicates a turn to the East. This occurs because of the magnetic compass's inherent lagging response to changes in headings.

As the left turn begins, the compass experiences what is known as "magnetic dip." The magnetic field does not immediately align with the new heading, and because of this, the compass card under-represents the turn. It behaves as though the aircraft is turning more toward the East than it actually is, creating a momentary indication that suggests a turn toward East.

This characteristic of the magnetic compass is crucial for pilots to understand, as it affects their navigation and the ability to accurately interpret compass readings during turns. Recognizing the compass's behavior helps pilots anticipate and compensate for any compass errors during maneuvers.