FAA Aircraft Dispatcher Practice Exam

How is absolute altitude defined?

1. Height above sea level

2. Height above the lowest point in the area

3. Height above mean sea level

4. Height above ground level

The correct answer is: Height above ground level

Absolute altitude is defined as the height of an aircraft above the terrain directly beneath it, which corresponds to the height above ground level (AGL). This measurement provides critical information for pilots and dispatchers, especially when considering terrain clearance during takeoff, landing, and flight maneuvers in proximity to the ground. Knowing the absolute altitude is essential for safe navigation, particularly in mountainous or uneven terrain where variations in ground height can impact flight safety. When understanding the other definitions, height above sea level typically refers to a vertical distance based on a reference point such as the average sea level, which is not the same as absolute altitude. The lowest point in the area could also become confusing because it doesn’t provide a standard reference and could vary significantly. Finally, height above mean sea level is a measurement that refers to an aircraft's altitude related to the average sea level, which is distinct from absolute altitude since it does not account for the actual terrain immediately below the aircraft.