Which instrument displays the aircraft's position relative to North?

The heading indicator is the instrument that displays the aircraft's position relative to North. It does this by providing the pilot with a continuous readout of the aircraft's heading in degrees, measured clockwise from true North. This information is crucial for navigation, as it allows the pilot to maintain a desired course and make necessary adjustments based on compass readings and other navigational data.

While the altimeter measures the aircraft's altitude and the Horizontal Situation Indicator (HSI) provides navigation information, including position relative to a specific course, it is the heading indicator that specifically relates to the aircraft's orientation with respect to North. Navigation lights, on the other hand, are for visibility and do not provide any positional information in the manner that the heading indicator does. Thus, the heading indicator serves a key role in ensuring that pilots have up-to-date information about their aircraft's heading, which is integral for safe and effective navigation.