FAA Ground School Practice Test

The primary function of the altimeter is to measure what?

1. Airspeed

2. Altitude

3. Vertical speed

4. Rate of climb

The correct answer is: Altitude

The primary function of the altimeter is to measure altitude. An altimeter determines the aircraft's height above a reference point, typically sea level. It does this by measuring the atmospheric pressure and computing altitude based on the standard atmosphere pressure at sea level. As the aircraft climbs or descends, the air pressure changes, allowing the altimeter to reflect the current altitude. Understanding the altimeter's role is crucial for pilots, as maintaining the correct altitude is vital for safe flight operations, navigation, and avoiding terrain and obstructions. Accurate altitude readings help ensure compliance with air traffic control instructions and adherence to airspace regulations. While airspeed, vertical speed, and rate of climb are important aspects of flight, they are measured by different instruments. Airspeed is monitored with aairspeed indicator, vertical speed is measured with a vertical speed indicator, and rate of climb relates to the performance of the aircraft in relation to its altitude but is not the primary function of the altimeter.