Class C airspace is used around airports with moderate traffic levels.
The airspace is charted on a VFR Sectional by 2 magenta circles. Within these magenta circles the floor and the ceiling of the Class C airspace is defined.
The airspace consists of 2 circles centered on the airport. The inner circle has a radius of 5 NM while the outer circle has a 10 NM radius. The inner circle begins at the surface and continues to 4000 ft AGL. The outer circle begins at 1200 ft AGL and continues to 4000 ft AGL. There is a 20 NM ring around all Class C airports referred to as the “Outer Area.” This area is not part of the Class C airspace. The outer area begins at the lower limit of radio/radar coverage and continues up to the upper limit of Approach Control's delegated airspace. As stated on VFR Sectional Charts you are asked to contact approach control within 20 NM of the airport.
Prior to entry, you must establish radio contact with ATC. If ATC responds with, "(Your aircraft call sign), standby," then contact has been established. If ATC does not use your call sign, contact has not been established.
A transponder with Mode C is required in and above all Class C airspace up to 10,000 ft MSL.
VFR traffic must remain 500 ft below, 1000 ft above, and 2000 ft horizontal separation from clouds with 3 miles of visibility.