Private Pilot Private Exam

Which instrument becomes inoperative if the pitot tube is clogged?

1. Altimeter

2. Airspeed

3. Vertical speed indicator

4. Heading indicator

The correct answer is: Airspeed

When the pitot tube becomes clogged, the airspeed indicator is impacted because it relies on dynamic pressure from the airflow through the pitot tube to measure the aircraft's speed. The pitot tube collects air pressure data from the surrounding atmosphere, and when it is blocked, the airspeed indicator can no longer receive this critical information. As a result, the instrument will either show a constant reading or drop to zero, indicating that it is inoperative. The altimeter, vertical speed indicator, and heading indicator do not connect directly to the pitot tube; they operate based on static pressure rather than dynamic pressure. Therefore, they can still function normally even if the pitot tube is clogged. Understanding the role of the pitot tube is essential for recognizing how critical it is for airspeed measurement, highlighting the importance of regular checks and maintenance to ensure it remains clear and operational.