Definition
Class C airspace is controlled airspace surrounding airports that have an operational control tower, are serviced by a radar approach control, and meet certain passenger or operations thresholds. It generally extends from the surface to 4,000 feet above the airport elevation, with an inner core typically 5 nautical miles in radius from the surface up, and an outer shelf typically 10 nautical miles in radius from 1,200 feet above the airport elevation up. Two-way radio communication with ATC must be established before entering, and all aircraft receive ATC services including radar separation between IFR and VFR traffic.
Plain English
Class C is the controlled airspace around medium-sized, busier airports. To fly into it, you must first talk to ATC and get a response that includes your call sign. ATC will then watch you on radar and help keep you separated from other traffic.
Context Anchor
You will see Class C on aeronautical charts around busier airports and in airspace discussions when planning arrivals, departures, or routes near controlled airports.
Derivation
The U.S. airspace classification system uses letters A through G, adopted in 1993 to align with ICAO standards. 'Class C' simply marks its place in that lettered hierarchy — busier than Class D, less restrictive than Class B.
Why Pilots Care
Pilots must establish two-way radio communication with ATC before entering and operate a transponder with altitude reporting, ensuring safe separation from other traffic.
Intuition Check
Do not read Class C as a difficulty level or a rating of airport quality. It is a specific airspace category with specific entry, communication, and equipment requirements.
Example Sentence 1
Before entering the Class C surface area, the pilot called approach and waited until the controller responded with their call sign.
Example Sentence 2
Operating inside Class C airspace requires a transponder with altitude encoding capability.