Which of the following is not a pitot-static instrument?

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

Answer: (D)

Understanding air data versus attitude sensing helps here. The pitot-static system provides the air data instruments with external pressures: dynamic pressure from the pitot tube and static pressure from the static port. The airspeed indicator uses both pitot (dynamic) and static pressures to show speed; the altimeter uses static pressure to indicate altitude; the vertical speed indicator monitors how quickly static pressure is changing to show climb or descent rate. The attitude indicator, however, is a gyroscopic instrument that shows the aircraft’s orientation relative to the horizon and is powered by a vacuum or electric source rather than by pitot-static pressures. Because it doesn't rely on pitot-static pressures, it is not a pitot-static instrument.