What is the function of a turn coordinator?

The turn coordinator is an essential instrument in an aircraft, specifically designed to indicate the aircraft's rate of turn. It provides pilots with a visual representation of how quickly the aircraft is turning, typically expressed in degrees per second. This information is crucial for maintaining proper flight control during turns and ensuring the aircraft does not exceed safe turn rates that could lead to a loss of control or excessive banking.

When flying, especially in instrument meteorological conditions (IMC) where visual cues are limited, the turn coordinator aids in achieving standard rate turns—where the aircraft completes a 360-degree turn in two minutes, or three degrees per second. This enables pilots to navigate effectively and maintain a safe flight path.

The other options, while related to flying, do not accurately describe the primary function of the turn coordinator. Fuel efficiency monitoring, descent rates, and compass heading are managed through other instruments like the fuel gauge, altimeter, and magnetic compass or heading indicator, respectively. Understanding the role of the turn coordinator helps pilots interpret crucial data for safe and effective aircraft operation.