How does the magnetic compass indicate direction?

The magnetic compass indicates direction by utilizing magnetized needles that are mounted on a float assembly. This design allows the needles to pivot freely and align themselves with the Earth's magnetic field. When the aircraft changes direction, the compass's magnetized needle adjusts accordingly to point towards magnetic north, providing the pilot with a reliable indication of the aircraft's heading.

The float assembly is crucial because it minimizes friction, allowing for smooth movement of the needle and ensuring accurate readings. As the aircraft turns, the needle will settle in a position that reflects the new heading, which is essential for navigation, particularly in visual flight rules (VFR) operations.

This method contrasts sharply with other technologies that may involve optical sensors or gyroscopic systems, which do not directly provide directional information based on magnetic orientation. Measuring barometric pressure, while important for certain flight parameters like altitude, is unrelated to directional indication.