During a constant airspeed climb, what is the primary pitch instrument used?

In a constant airspeed climb, the primary pitch instrument used is the attitude indicator. The attitude indicator provides essential information about the aircraft's orientation relative to the horizon. It shows whether the aircraft is climbing, descending, or level and helps the pilot maintain the desired climb rate while ensuring that the airplane’s pitch is properly managed for the set airspeed.

During a climb, achieving and sustaining the correct pitch attitude is crucial for performance and safety. The attitude indicator helps the pilot ensure that the aircraft is not climbing too steeply or losing airspeed. While the airspeed indicator tracks the speed, and the altimeter measures altitude, the attitude indicator directly informs the pilot about how to adjust the pitch for both maintaining the climb and adhering to the target airspeed. In this context, the vertical speed indicator can show how quickly the aircraft is climbing, but it does not directly inform pitch adjustments like the attitude indicator does.