What is the primary pitch instrument when establishing a constant altitude standard-rate turn?

The primary pitch instrument when establishing a constant altitude standard-rate turn is the altimeter. This instrument measures the aircraft's altitude in relation to sea level, which is crucial for maintaining a consistent altitude during any maneuver, including a turn. When performing a standard-rate turn, it is essential to monitor the altitude closely to ensure that the aircraft does not inadvertently climb or descend.

In a standard-rate turn, the aircraft needs to maintain a specific bank angle while ensuring that the altitude remains constant. The altimeter provides immediate feedback on any changes in altitude, allowing the pilot to make necessary adjustments to maintain level flight. Although the attitude indicator is essential for maintaining the correct bank for the turn, it does not directly indicate altitude changes.

Other instruments, such as the vertical speed indicator and airspeed indicator, provide supporting information, but they are not primarily used for maintaining altitude during a turn. The vertical speed indicator shows whether the altitude is increasing or decreasing, while the airspeed indicator reflects changes in speed but does not directly relate to altitude maintenance. Thus, the altimeter is the most critical instrument for ensuring a constant altitude during a standard-rate turn.