First, we can tell whether the airport has a control tower or not, just by looking at the symbol. A blue symbol indicates that an airport is towered, while a magenta symbol indicates a non-towered airport.

In the world of aviation, an airport is considered "controlled" if it has an operational Air Traffic Control (ATC) tower that manages the flow of aircraft on the ground and in the immediate vicinity. For pilots in 2026, the primary way to identify a controlled airport is by looking at an Aeronautical Sectional Chart; controlled airports are depicted in blue, while uncontrolled (non-towered) airports are shown in magenta. Additionally, a controlled airport will have specific radio frequencies listed for "Tower," "Ground," and "Clearance Delivery." Visually, the presence of a physical control tower is the most obvious sign, but pilots also check the "Airport/Facility Directory" to see if the tower operates 24/7 or only during specific hours. If the tower is closed (e.g., late at night at a smaller regional airport), the airport temporarily becomes uncontrolled, and pilots must broadcast their intentions on a Common Traffic Advisory Frequency (CTAF).