What does the altimeter read during a climb?

• A. It stays constant regardless of altitude
• B. It decreases, indicating a loss of altitude
• C. It rises as the aircraft ascends, reflecting increased altitude
• D. It fluctuates due to atmospheric pressure changes

Answer: (C)

The altimeter is a sensitive instrument that measures the altitude of an aircraft based on air pressure. During a climb, the aircraft ascends toward higher altitudes, which results in a decrease in the surrounding air pressure. As the aircraft climbs, the altimeter responds to this reduction in pressure by indicating an increase in altitude. Therefore, the altimeter reading rises, corresponding with the actual climb of the aircraft.

This correlation is fundamental to how altimetry works, as it relies on the standard atmospheric pressure lapse rate. For pilots, understanding the behavior of the altimeter during a climb is crucial for maintaining safe altitude awareness and ensuring compliance with regulations regarding altitude separation and traffic avoidance.