Which instrument operates on the Pitot-static system?

The airspeed indicator operates on the Pitot-static system, which is a crucial component of flight instrumentation. This system uses both the dynamic pressure from the Pitot tube and the static pressure from the static ports to measure the aircraft's airspeed.

The Pitot tube measures the total pressure, which includes both static pressure and dynamic pressure caused by the aircraft's movement through the air. The static ports measure ambient atmospheric pressure. The airspeed indicator then calculates the difference between these pressures to determine how fast the aircraft is moving relative to the surrounding air.

In contrast, the other instruments mentioned do not operate on the Pitot-static system. The magnetic compass relies on the Earth's magnetic field for navigation and does not measure air pressure. The vertical speed indicator is also part of the static system but focuses on changes in altitude rather than airspeed. Similarly, the attitude indicator provides information about the aircraft's orientation relative to the horizon and does so using gyroscopic principles, not pressure measurements. Therefore, the airspeed indicator is the only instrument listed that directly relies on the Pitot-static system for its operation.