What is the maximum altitude for uncontrolled airspace?

The maximum altitude for uncontrolled airspace is 14,500 feet MSL, not 18,000 feet MSL. In the United States, Class G airspace, which is the category of uncontrolled airspace, extends from the surface up to 14,500 feet MSL. This means that below 14,500 feet, pilots can operate without an air traffic control clearance, and there are fewer regulations in place compared to controlled airspace.

Above 14,500 feet MSL, the airspace transitions into controlled airspace, which is generally Class E airspace, where ATC services are required. Therefore, 14,500 feet MSL serves as a critical boundary for understanding where uncontrolled airspace ends and controlled airspace begins. This distinction is important for pilots to ensure they are operating within the correct regulations and safely navigating through various airspace classifications.