How does icing on the pitot tube affect altitude measurement?

Icing on the pitot tube can lead to erroneous altitude readings because the pitot tube is responsible for measuring airspeed by comparing the dynamic pressure of the air with the static pressure. When ice obstructs the pitot tube, it disrupts the flow of air into the tube, which affects the pressure measurements it relies on to determine airspeed.

In aircraft, the altitude is often derived from indicated airspeed as the aircraft ascends and descends, and any incorrect readings from the pitot tube can lead pilots to misinterpret their altitude. For example, if icing blocks the sensor or distorts the pressure readings, the aircraft might report a false altitude, potentially leading to hazardous situations such as flying too low or too high compared to intended flight levels.

Thus, the presence of ice on the pitot tube can indeed result in unreliable altitude data, highlighting the critical importance of ensuring all sensors are clear and functioning correctly for accurate flight operations.