What instrument utilizes Static and Dynamic pressure?

• A. Airspeed Indicator
• B. Altimeter
• C. Vertical Speed Indicator
• D. Attitude Indicator

Answer: (A)

The main concept is that airspeed is determined from the difference between two pressures: dynamic pressure, which comes from the air flowing into the pitot tube, and the ambient static pressure from the static port. The airspeed indicator uses this pressure difference to drive its mechanism and display airspeed. In calm terms, as you move faster, the stagnation (dynamic) pressure increases while the static pressure stays the same, and that bigger difference makes the indicator show a higher airspeed. Because the instrument relies on both pressures, it is the one that uses static and dynamic pressure.

To see why the others don’t fit: the altimeter measures altitude using static pressure alone, not dynamic pressure. The vertical speed indicator responds to the rate of change of static pressure over time, again not using dynamic pressure. The attitude indicator is powered by a gyroscope and has no need for pressure information. So the instrument that truly uses both static and dynamic pressure is the airspeed indicator.