How does the airspeed indicator behave with a blocked pitot tube during a climb?

In the case of a blocked pitot tube during a climb, the airspeed indicator will freeze at the last reading. This is because the pitot tube is responsible for measuring dynamic pressure, which is necessary for the airspeed indicator to function correctly. When the tube is blocked, it cannot adjust for changes in air pressure as the aircraft climbs.

As the aircraft ascends, the static pressure decreases, but the pitot tube will no longer be able to reflect that change since it is obstructed. Therefore, the airspeed indicator will not show a fresh reading corresponding to the aircraft's current speed, resulting in it retaining the last reading taken before the blockage.

This situation can lead to serious misunderstandings about the aircraft's performance, as the pilot may not realize that the airspeed reading is stale and not reflecting the actual conditions during the climb. It is important for pilots to be aware of this potential issue and check their instruments for proper functioning, particularly in critical phases of flight like climbing. Maintaining awareness of instrument operation and understanding how each instrument responds to various scenarios is crucial for safe flight operations.