What surrounds tower-controlled airports that do not have an associated Class B or C area?

Tower-controlled airports that do not have an associated Class B or C airspace are typically surrounded by Class D airspace. Class D airspace is specifically designated around airports with an operational control tower that is not part of a larger or more complex Class B or C airspace system.

The purpose of Class D airspace is to facilitate the safe and orderly flow of air traffic around the airport and provide pilots with information about traffic and conditions in the vicinity. Within this airspace, communication with the control tower is mandatory, which helps manage both arriving and departing traffic.

While Class E airspace surrounds areas that may not require a tower, it does not specifically correlate to the structure surrounding tower-controlled airports. Uncontrolled airspace does not surround tower-controlled airports, as it typically exists outside of the defined airspace zones managed by air traffic control. Special use airspace refers to designated areas that may have restrictions on entry, which is not applicable in this context. Therefore, Class D airspace is the most fitting description for the surrounding area of these airports.