Static system dump results in failure of which set of instruments?

• A. Altimeter, VSI, and Airspeed Indicator
• B. Altimeter
• C. VSI
• D. Airspeed Indicator

Answer: (A)

The instruments tied to ambient pressure are affected. The static pressure source from the Pitot-Static system feeds the altimeter, the vertical speed indicator, and the airspeed indicator. If the static system dumps, that static reference is lost, so:

• Altimeter loses its altitude reference and can freeze, follow an incorrect value, or behave erratically.

• Vertical speed indicator can no longer sense pressure change correctly, so it may read zero or become unreliable.

• Airspeed indicator relies on the difference between pitot (dynamic) pressure and static pressure; without a proper static reference, the indicated airspeed becomes unreliable or meaningless.

Since all three rely on the same static pressure, a static system dump causes them all to fail to indicate accurate information.