What is the function of the Turn and Slip Indicator?

The Turn and Slip Indicator plays a crucial role in aircraft operation by helping pilots execute coordinated turns. This instrument provides real-time feedback on the aircraft's yaw and roll, thus indicating whether the turn is coordinated, uncoordinated, or requires adjustment.

During a coordinated turn, the aircraft's rate of turn and the bank angle are aligned, and the Turn and Slip Indicator shows that the turn is executed properly without excessive lateral acceleration. If the ball in the instrument moves to one side, it indicates that the aircraft is skidding or slipping, which requires corrective action from the pilot to maintain control and ensure safety during the maneuver. This visualization of the aircraft's dynamics is essential for effective and safe navigation, especially in complex flight scenarios.

The other options focus on different aspects of flight instrumentation: measuring altitude, displaying true airspeed, and sensing atmospheric pressure, none of which pertain to the specific function of the Turn and Slip Indicator.