Which two pressures affect the pitot-static system?

Which two pressures affect the pitot-static system?

• A. static pressure and ambient pressure
• B. static pressure and dynamic pressure
• C. dynamic pressure and ambient pressure
• D. static pressure and dynamic pressure

Answer: (D)

The pitot-static system is driven by two pressures: static pressure and dynamic pressure. Static pressure is the ambient air pressure surrounding the aircraft. Dynamic pressure comes from the motion of the aircraft through the air and increases with speed, described by q = 1/2 ρ V^2. The pitot tube measures stagnation (total) pressure, which equals static plus dynamic pressure, and the airspeed indicator derives speed from the difference between stagnation and static pressures (the dynamic component). Since ambient pressure essentially equals static pressure in this context, the two pressures that matter are static and dynamic.

The pitot-static system is driven by two pressures: static pressure and dynamic pressure. Static pressure is the ambient air pressure surrounding the aircraft. Dynamic pressure comes from the motion of the aircraft through the air and increases with speed, described by q = 1/2 ρ V^2. The pitot tube measures stagnation (total) pressure, which equals static plus dynamic pressure, and the airspeed indicator derives speed from the difference between stagnation and static pressures (the dynamic component). Since ambient pressure essentially equals static pressure in this context, the two pressures that matter are static and dynamic.