What is static pressure?

• A. The total pressure in front of the pitot tube.
• B. The difference between stagnation and dynamic pressure.
• C. The pressure inside the cabin.
• D. The ambient air pressure sensed by the pitot-static system.

Answer: (D)

Static pressure is the ambient atmospheric pressure at the aircraft’s location, as sensed by the static ports of the pitot-static system. It represents the outside air pressure at the aircraft’s altitude, not affected by the airplane’s forward motion when the ports are correctly located. This pressure serves as the baseline for the pitot-static instruments: the difference between stagnation (total) pressure measured by the pitot tube and this static pressure gives dynamic pressure, which is used to determine airspeed. The cabin pressure is a separate system, and the stagnation pressure is the pressure in front of the pitot tube, not static pressure.