What classification applies to airspace overlapping with regulated towers but not continuously in operation?

Class D airspace is defined as controlled airspace that extends upward from the surface to a specified upper limit and is usually associated with airports that have operational control towers. This airspace is typically found surrounding airports with a Control Tower, and it is established where the need for air traffic control services exists to manage traffic arriving and departing from those airports.

One key characteristic of Class D airspace is that it only exists when the control tower is in operation. Therefore, if an airspace overlaps with a regulated tower but the tower is not continuously in operation, the airspace remains classified as Class D only when the tower is active. During times when the tower is closed, the classification may change based on local or federal regulations.

This classification is essential for pilots to understand, as it determines the rules and requirements for operating within that airspace, including communication and procedures that must be followed. Understanding why Class D is identified specifically in this context supports safe navigation and adherence to regulations in controlled airspace, especially in proximity to airports.