Instrument Flight Rules (IFR) Practice Exam 2025 - Free IFR Questions and Study Guide

When both the ram air input and the drain hole of the pitot system are blocked, the system will register the static pressure of the surrounding air as it does not have fresh ram air entering the pitot tube. In this scenario, the airspeed indicator effectively becomes a static pressure gauge, which indicates the static pressure minus the pressure drop due to changes in altitude.

During a climb, the airplane is moving to a lower pressure environment outside (as altitude increases), while the static pressure registered in the blocked pitot system does not change with the actual climb. Hence, as the altitude increases, the indicated airspeed will continue to indicate an increase, following the trend of the declining static pressure, leading to an apparent increase in indicated airspeed.

Therefore, the behavior of the indicated airspeed in this condition aligns closely with the situation described. It is crucial to recognize that in real life, relying on a blocked pitot system can lead to incorrect and misleading airspeed indications, which is critical for safe flight operations.