What type of instrument is a turn coordinator?

The turn coordinator is designed specifically to measure the rate of turn and provide information on the coordination of the aircraft's flight path. It plays a crucial role in helping pilots maintain controlled turns by indicating whether the aircraft is properly coordinated or if it is skidding or slipping during a turn.

This instrument provides key information in both visual and instrument flight conditions. The turn coordinator typically displays the rate of turn in degrees per second and may also show indications of proper bank angles required for various types of turns. By using the turn coordinator, pilots can ensure that their turns are executed safely and effectively, maintaining the intended flight path and preventing issues such as adverse yaw or an uncoordinated turn.

As for the other options, they relate to different types of instruments. For instance, measuring speed, rate of climb, or altitude pertains to other specific instruments, such as the airspeed indicator, vertical speed indicator, and altimeter, respectively. Each of these serves distinct functions that are not related to the coordination and rate of turn of the aircraft, highlighting the specialized role of the turn coordinator in aviation.