What is the altitude range for Class A airspace?

The altitude range for Class A airspace is indeed from 18,000 feet Mean Sea Level (MSL) to Flight Level 600 (FL600). Class A airspace is primarily designated for high-altitude flight, which is critical for the management of commercial air traffic.

This airspace is managed under strict rules requiring all aircraft to operate under Instrument Flight Rules (IFR), ensuring safety and efficiency in a high-density air traffic environment. Since this class of airspace exists above the majority of the general aviation flying, it requires pilots to receive air traffic control clearance before entering, promoting effective communication and minimizing the risk of collisions.

In contrast, other choices do not accurately define the altitude limits of Class A airspace. The provided ranges do not extend from 18,000 feet up to Flight Level 600, and instead fall within either general operating altitudes or correspond to different classes of airspace. The specificity of Class A’s altitude helps delineate its purpose and importance in airspace classification.