The radius of a procedural Outer Area of Class C airspace is normally

• A. 10 NM
• B. 15 NM
• C. 20 NM
• D. 25 NM

Answer: (C)

Class C airspace is designed with a core area close to the airport and an outer area that extends farther out. When radar coverage isn’t available, a procedural outer area is used to provide controlled airspace without radar support. In this case, the outer area normally extends to twenty nautical miles from the airport. Within that area, pilots must establish two-way radio communication with ATC and follow the assigned procedures (including any transponder requirements) to ensure separation and sequencing. That’s why twenty nautical miles is the radius for a procedural Outer Area.