What does the round magenta symbol represent on a Cincinnati sectional chart?

The round magenta symbol on a Cincinnati sectional chart indicates a non-towered airport with a hard-surfaced runway. This symbol is used to help pilots quickly identify airports that are not equipped with an air traffic control tower, allowing for smaller airports to be recognized and understood in terms of their operational structure. The magenta color signifies that the airport is available for public use, and the hard-surfaced runway indicates that it likely has better landing conditions compared to unpaved alternatives.

Understanding these symbols and their meanings is essential for navigation and safety during flight, as it allows pilots to plan their approaches to airports that may not have the same level of services as towered airports.