What is the altitude range for Class A airspace?

Class A airspace extends from 18,000 feet up to 60,000 feet above sea level. This classification is crucial for the management of high-altitude flight primarily because it is the zone where all flights are required to operate under instrument flight rules (IFR). The specific altitude range ensures that air traffic is effectively controlled and coordinated, accommodating the high density and complexity of air traffic in this airspace segment, particularly in areas of commercial flight. This airspace structure helps maintain safety and efficiency among the various types of aircraft operating in the national airspace system.