How airspace is organized
8 min readLesson 30 of 593D lab
By the end of this lesson you'll be able to:
- Tell controlled from uncontrolled airspace
- Name the six airspace classes
- Recognize each class on a sectional chart
U.S. airspace is divided into controlled airspace (Classes A, B, C, D and E), where ATC provides services to IFR flights, and uncontrolled airspace (Class G). "Controlled" doesn't mean you always need to talk to ATC as a VFR pilot; that depends on the class.
| Class | Where | On the sectional |
|---|---|---|
| A | 18,000 ft MSL up to and including FL600 | Not shown |
| B | Around the busiest airports, surface to usually 10,000 ft MSL, shaped like an upside-down wedding cake | Solid blue lines |
| C | Around busy airports with a control tower and radar approach control, typically surface to 4,000 ft above the airport | Solid magenta lines |
| D | Around airports with an operating control tower, typically surface to 2,500 ft above the airport | Dashed blue lines |
| E | All other controlled airspace | Magenta vignette (starts at 700 AGL), dashed magenta (starts at the surface), or not marked (usually starts at 1,200 AGL) |
| G | Everything that isn't A-E, mostly close to the ground | Implied beneath Class E floors |
The numbers in the airspace boxes on the chart are in hundreds of feet MSL. "80/SFC" in a Class C sector means the airspace goes from the surface to 8,000 ft MSL. "T" means the top is the bottom of the Class B above it.
See it in 3D. The airspace lab lets you fly an airplane through every class and see what you need to enter each one. It makes the wedding cake shapes click fast.
Key takeaways
- Controlled: A, B, C, D, E. Uncontrolled: G.
- Chart colors: B solid blue, C solid magenta, D dashed blue, E surface dashed magenta / 700 AGL vignette.
- Class A starts at 18,000 ft MSL; it's IFR only.
What the examiner may ask
Practice answering out loud before you open each answer.
What class of airspace is your home airport in?
Know it, the ceiling, and what changes when the tower closes.
Where does Class E airspace typically begin?
At 1,200 ft AGL, at 700 ft AGL in a magenta vignette, at the surface around some airports (dashed magenta), or at 14,500 ft MSL.
What does '40/SFC' in a Class C sector mean?
The airspace extends from the surface to 4,000 feet MSL.
Common mistakes
- Reading airspace altitudes as AGL when they're MSL.
- Missing a Class E surface area and its weather minimums.
- Forgetting that Class D can revert when the tower closes.
Read it in the FAA sources
Go deeper on the site
Lesson check
Get every question right to complete the lesson. Take your time; wrong answers explain why.
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