Which instrument uses pitot-tubes to determine airspeed?

The airspeed indicator measures the speed of an aircraft relative to the surrounding air using pitot-tubes. These tubes are designed to measure dynamic air pressure, which increases with airspeed. The airspeed indicator utilizes this pressure difference, typically by combining the static pressure measured from static ports, to display the aircraft's airspeed on its dial. This functionality is crucial for pilots, as it informs them of their speed during different phases of flight.

Other instruments listed serve different purposes. For instance, the accelerometer measures acceleration and deceleration rather than airspeed. The altimeter quantifies altitude based on barometric pressure, and the vertical speed indicator measures the rate of climb or descent. Each of these instruments provides essential information for flight operation, but it is the airspeed indicator that specifically utilizes pitot-tubes to determine how fast the aircraft is moving through the air.