Airspace Description
A Class D airspace area is designated at smaller airports having sufficient traffic volume to necessitate an air traffic control tower. It normally extends four nautical miles from the primary airport, from the surface up to 2,500 feet AGL.
Communications Requirement
Two way radio communications with the tower must be established prior to entering the airspace.
Equipment Requirements
A two way radio is required to enter the airspace.
Part Time Towers
It is common for a control tower to operate only during certain hours. When the tower is closed, the airspace will no longer be a Class D airspace. The airspace commonly becomes Class E airspace.
ยง 91.129 Operations in Class D airspace.