FAA Instrument Rating Written Test 2025 – 400 Free Practice Questions to Pass the Exam

The correct answer is that higher temperatures cause indicated altitude to be higher than true altitude. This occurs due to the principles of atmospheric pressure and temperature.

When the temperature of the atmosphere increases, the air becomes less dense. Altimeters work by measuring atmospheric pressure and translating that pressure reading into an altitude. If the air is warmer, the pressure at a given altitude will be higher than it would be in cooler air, leading the altimeter to provide a reading that suggests a higher altitude than the actual altitude.

This phenomenon is crucial for pilots to understand, as temperature variations can significantly impact flight safety and navigation. Therefore, during warmer weather, pilots may find that their altimeter indicates a higher altitude than they are truly at, which can affect their ability to maintain safe separation from the terrain and other aircraft.