What is a requirement for flying in Class A airspace?

Flying in Class A airspace requires an IFR (Instrument Flight Rules) flight plan. This is due to the nature of Class A airspace, which extends from 18,000 feet MSL (mean sea level) up to 60,000 feet MSL in the United States. It is primarily used for high-altitude flights where instrument flying is essential due to air traffic density and varying weather conditions.

In Class A airspace, pilots must operate under IFR rules, which ensure safety and provide oversight by air traffic control (ATC). This allows ATC to manage the complex air traffic environment, directing aircraft to maintain safe separation distance and altitude, which is particularly critical at altitudes where multiple aircraft operate closely together.

Other flight plans or operations, such as those for visual flight rules (VFR), are not permitted within Class A airspace since they rely on visual references, which are not feasible or safe at such high altitudes. Hence, an IFR flight plan is necessary to ensure compliance with the specific requirements and restrictions of operating in Class A airspace.