If the altimeter is adjusted from 29.20 to 30.00, what change would be observed?

When the altimeter is adjusted from 29.20 inches of mercury (inHg) to 30.00 inHg, the indicated altitude would appear to go up. This occurs because altimeters are designed to display height above a reference pressure level.

The altimeter measures the atmospheric pressure and compares it to a standard pressure setting, which is typically 29.92 inHg at sea level. When the setting is changed to a higher pressure of 30.00 inHg, the altimeter interprets that the aircraft is at a higher altitude than it actually is because the air pressure at a higher altitude is lower than that at a higher pressure setting. Therefore, as you raise the altimeter setting, it reads a higher altitude than the actual altitude; this is why the altitude appears to go up.

This is crucial for pilots to understand, as incorrect altimeter settings can lead to significant altitude misjudgments, which can be particularly hazardous during flight operations. Correct altitude indications are essential for maintaining safe separation from terrain and other aircraft.