HA! That happened to me last month! An ANT got into the pitot tube and blocked the air flow. You have something keeping the air inside the tube. This is common with ice buildup on the tube. An AN=NT was a new one for me!
Airspeed, altimeter, and vertical speed indicator
If the static vents become clogged, the airspeed indicator, altimeter, and vertical speed indicator will become inoperative. These instruments rely on static pressure to provide accurate readings, so any blockage in the static vents will disrupt their functioning.
An airspeed indicator is an aviation instrument which displays an aircraft's current airspeed.
The airspeed indicator or airspeed gauge is an instrument used in an aircraft to display the airspeed in knots
It's an airspeed indicator that compensates for outside temperature and barometric pressure at altitude.
Airspeed Indicator.
Alexander Ogilvie from England
An airspeed indicator works by measuring the difference between the ram air pressure from the pitot tube (which faces forward into the airstream) and the static air pressure from the static port. The difference in pressures is converted into an airspeed reading on the instrument display. As the aircraft moves through the air, the pressure differential changes, and the airspeed indicator reflects these changes in real time.
The airspeed indicator operates based on the difference between the pressure of the pitot tube (ram air pressure) and the static port (ambient air pressure). As the aircraft moves through the air, the pressure difference changes, which is translated into an airspeed reading on the indicator. The indicator is calibrated to display the indicated airspeed, which may differ from the true airspeed due to factors like altitude and instrument errors.
some V speeds are not indicated, It doesn't show true airspeed or ground speed.
the airspeed indicator works by measuring the increase in air pressure caused by the moving aircraft
Airspeed indicator, alitimeter, and vertical speed indicator.