Which instrument senses both roll and yaw due to gimbal cant?

• A. Turn indicator
• B. Turn coordinator
• C. Attitude indicator
• D. Altimeter

Answer: (B)

A gyroscopic instrument can be made to respond to motion about multiple axes by tilting its gimbal. In a turn coordinator, the gyro is mounted with its axis canted upward, so it senses both yaw rate (rate of turn) and roll rate (bank). This means when you roll into a turn, the instrument deflects in response to that roll, and as the aircraft continues to yaw, it continues to respond to the turning motion as well. The combined sensitivity provides a quicker, more helpful indication of how the airplane is moving through the air, aiding in turn coordination.

The other instruments don’t behave the same way. The turn indicator uses a vertically mounted gyro, so it mainly senses yaw rate and doesn’t reflect roll early in the maneuver. The attitude indicator shows the aircraft’s bank and pitch but isn’t a turn-rate instrument; it demonstrates attitude rather than rate of turn. The altimeter measures altitude.