The airspeed indicator measures the pressure difference between static air and ram air entering the pitot tube. It translates this differential pressure into a speed reading, usually in knots. It features color-coded arcs to warn the pilot of stall speeds, normal operating ranges, and structural limits.
Heard on the job
I tapped the glass but the airspeed indicator is still reading zero, so we definitely have a blocked pitot tube.
Also heard as
- ASI