How does a pitot-static system work?

The pitot-static system is fundamental to the operation of several aircraft instruments, including the airspeed indicator, altimeter, and vertical speed indicator. It works by measuring two types of pressure: static pressure and dynamic pressure.

Static pressure is the atmospheric pressure surrounding the aircraft, while dynamic pressure is the pressure exerted by the air as the aircraft moves through it. The pitot tube measures dynamic pressure, which is the difference between total pressure (measured with the pitot tube) and static pressure (measured from the static ports located on the aircraft's fuselage).

The airspeed indicator uses this combination of pressures to calculate the aircraft's speed relative to the air. The altimeter, on the other hand, uses static pressure alone to determine altitude by comparing the current atmospheric pressure to a standard reference. The vertical speed indicator also derives its information from static pressure changes over time.

In summary, the pitot-static system's ability to measure both static and dynamic pressure is what allows it to provide crucial information about airspeed, altitude, and rate of climb or descent, making it essential for safe aircraft operation.