FAA Private Pilot Helicopter (PRH)Navigation and AirspaceMedium
A pilot examining a sectional chart notes an airport surrounded by two concentric magenta circles, an inner circle with a 5 NM radius and an outer circle with a 10 NM radius. What best describes the vertical structure of this airspace?
- AAn inner core from the surface to 4,000 feet AGL and an outer shelf from 1,200 to 4,000 feet AGL
- BA single circle extending from 1,200 feet AGL to the surface only
- CAn inner core from 700 feet AGL to 10,000 feet MSL with no outer shelf
- DA single shelf extending from the surface to 10,000 feet MSL
Show answer & explanationAnswer & explanation
Correct answer: A. An inner core from the surface to 4,000 feet AGL and an outer shelf from 1,200 to 4,000 feet AGL
Class C airspace has a two-tier design: an inner core (surface to 4,000 feet AGL, 5 NM radius) and an outer shelf (1,200 to 4,000 feet AGL, extending to 10 NM radius). This layout allows aircraft to fly beneath the outer shelf without entering Class C.
Why the other options are wrong
- B. Class C includes a surface core, not just a shelf starting at 1,200 feet.
- C. This description does not match the actual Class C dimensions.
- D. Class C does not extend to 10,000 feet MSL as a single shelf.
Class C Airspace
Controlled airspace around airports with a radar approach control and operating tower, depicted by solid magenta circles.
- Inner core: surface to 4,000 ft AGL, 5 NM radius
- Outer shelf: 1,200 to 4,000 ft AGL, 10 NM radius
- Two-way radio communication must be established before entry
Memory trick: Class C looks like a wedding cake — a small tight core topped by a wider shelf.