FAA Ground School Practice Test

What is pressure altitude?

1. The altitude indicated when the barometric pressure scale is set to standard conditions

2. The altitude when the altimeter is set to 29.92

3. The vertical distance of the aircraft above sea level

4. The altitude above ground level

The correct answer is: The altitude when the altimeter is set to 29.92

Pressure altitude is defined as the altitude indicated when the altimeter is set to the standard barometric pressure of 29.92 inches of mercury (Hg). This standard setting is crucial for ensuring that altitude measurements are consistent, particularly when pilots are flying at higher altitudes where atmospheric pressure may vary significantly from standard conditions. By setting the altimeter to this specific pressure, pilots can ensure that they are using a common reference for altitude that adheres to the International Standard Atmosphere (ISA) model, thereby allowing for better communication and coordination with air traffic control. This definition highlights the importance of barometric pressure in determining altitude, especially in aviation operations where accurate altitude readings are vital for safety and navigation. Understanding pressure altitude is fundamental for pilots, as it impacts aircraft performance, navigation, and compliance with air traffic control regulations.