Private Pilot Private Exam

How does warm air temperature affect altimeter readings?

1. It raises pressure levels, indicating higher altitude

2. It lowers pressure levels, indicating lower altitude

3. It maintains accurate altitude readings

4. It causes random fluctuations in altitude indications

The correct answer is: It raises pressure levels, indicating higher altitude

Warm air temperature influences altimeter readings by causing the altimeter to indicate a higher altitude than the actual altitude. This occurs because warm air is less dense, resulting in lower pressure. As the density of the air decreases, the pressure at a given altitude is also reduced. An altimeter measures air pressure and translates that pressure into altitude. When the temperature is warmer, the pressure levels at a specific altitude are lower than they would be under standard temperature conditions. Consequently, if pilot is using an altimeter set to standard pressure settings, the reading will suggest that the aircraft is at a higher altitude than it truly is. Understanding how temperature affects air density and thus pressure is crucial for accurate altitude readings, as fluctuations may lead to flight safety issues.