Which pitot tube is described as 'pitot-only'?

• A. P1
• B. P2
• C. P3
• D. None of the above

Answer: (C)

The question tests understanding of what “pitot-only” means in pitot tube terminology. A pitot tube that is described as pitot-only measures stagnation (total) pressure from the oncoming air and does not have a static pressure port to sense ambient pressure. In practice, airspeed or other dynamic-pressure-related readings typically rely on both pitot (total) and static pressures, so a pitot-only tube lacks the static reference.

The correct option is the tube that has only a forward-facing opening for pitot pressure and no static-port openings. The other tubes include static pressure ports, making them pitot-static tubes, not pitot-only.