Guides · Path step 1 · ASP
Airspace Classes
Six classes. Different floors, radios, and clearances. Learn the picture on the sectional, then the table.
Overview
U.S. airspace is six classes, A through G. Each class has its own floor, radio rules, and entry requirements. Learn the picture on the sectional first, then the table.
Hold
Remember: "A" is the most restrictive (ATC clearance required), "G" is the least restrictive (uncontrolled). Think alphabetically from most to least controlled.
Class A Airspace
Characteristics
- From 18,000 feet MSL up to and including FL600 (60,000 feet)
- Includes all airspace overlying the states and waters within 12 miles of the U.S. coast
- Always controlled airspace
Requirements
- ATC Clearance Required - Must have explicit clearance to enter
- IFR Flight Only - No VFR flights permitted
- Instrument Rating Required - Pilot must hold an instrument rating
- Two-Way Radio - Required for communication
- Transponder - Mode C and ADS-B Out required (§91.215 / §91.225)
Class B Airspace
Characteristics
- Surrounds the nation's busiest airports (e.g., JFK, LAX, ORD)
- Typically surface to about 10,000 feet MSL; the charted top is controlling
- Shaped like an upside-down wedding cake with multiple layers
Requirements
- ATC Clearance Required - Must receive explicit clearance
- Student pilots - 61.95 endorsement: ground and flight training plus a logbook endorsement for that specific Class B. 91.131 is the operating rule and limits student solo at the primary airport unless that airport is listed in the endorsement
- Two-Way Radio - Required for communication
- Transponder - Mode C and ADS-B Out required
Written
Class B typically extends from the surface to about 10,000 feet MSL. The charted top is controlling. An ATC clearance is required for entry.
Class C Airspace
Characteristics
- Surrounds airports with moderate traffic levels
- Typically an inner surface area 5 NM radius, surface to 4,000 feet above airport elevation (charted MSL), and an outer area 10 NM radius from 1,200 to 4,000 feet above airport elevation. Individually tailored; read the chart.
Requirements
- Two-Way Radio Contact - Must establish contact before entering
- Transponder - Mode C and ADS-B Out required
- No ATC Clearance Required - But must communicate
Class D Airspace
Characteristics
- Surrounds airports with operating control towers
- Typically 2,500 feet above airport elevation, charted in MSL
- Radius typically 4-5 NM from airport
Requirements
- Two-Way Radio Contact - Must establish contact before entering
- Transponder / ADS-B Out - Class D itself does not trigger Mode C or ADS-B Out. You still need them if you are also in equipment airspace under §91.215 / §91.225 (for example the 30 NM Mode C veil, or at/above 10,000 feet MSL excluding at/below 2,500 feet AGL).
- No ATC Clearance Required - But must communicate
Class E Airspace
Characteristics
- Controlled airspace but no operating control tower
- Most common type of controlled airspace
- Typically extends up to but not including 18,000 feet MSL. Airspace above FL600 is also Class E.
- Includes:
- Federal airways (8 NM wide / 4 NM either side of centerline unless otherwise specified; 1,200 feet AGL up to but not including 18,000 feet MSL)
- Transition areas
- Enroute domestic areas
Common Class E Floors
- Magenta dashed line: Class E to the surface
- Magenta vignette/fade: Class E starts at 700 feet AGL
- Blue vignette: Class E starts at 1,200 feet AGL
- Blue dashed line: Class D (not a Class E floor)
Class G Airspace
Characteristics
- Uncontrolled airspace - No ATC jurisdiction
- Extends from surface up to the base of overlying controlled airspace
- Most common near small airports and rural areas
Requirements
- No ATC Clearance Required
- No Radio Required (but recommended)
- No Transponder Required - No Mode C or ADS-B Out requirement from the Class G letter alone. Equip if the flight is also in §91.215 / §91.225 equipment airspace (Mode C veil, ≥10,000 feet MSL with the 2,500 AGL exclusion, above Class B/C shelves, etc.).
- VFR Minimums Apply (14 CFR 91.155)
- At or below 1,200 feet AGL. Day: 1 SM visibility, clear of clouds. Night: 3 SM, 500 below / 1,000 above / 2,000 horizontal
- More than 1,200 AGL and below 10,000 MSL. Day: 1 SM, 500/1,000/2,000. Night: 3 SM, 500/1,000/2,000
- At or above 10,000 MSL and more than 1,200 AGL: 5 SM, 1,000 above / 1,000 below / 1 SM horizontal
Quick reference
| Class | Clearance | Radio | Mode C / ADS-B Out | VFR Allowed |
|---|---|---|---|---|
| A | Required | Required | Required (§91.215 / §91.225) | No |
| B | Required | Required | Required (§91.215 / §91.225) | Yes |
| C | No | Required | Required (§91.215 / §91.225) | Yes |
| D | No | Required | Not by class letter — see note | Yes |
| E | No | No | Not by class letter — see note | Yes |
| G | No | No | Not by class letter — see note | Yes |
Equipment note
Equipment note (Mode C / ADS-B Out). Mode C (§91.215) and ADS-B Out (§91.225) are separate rules and are mostly location-based, not a property of the Class D/E/G letter. After Jan 1, 2020, ADS-B Out is required in the airspace in §91.225(d), including: Class A (see §91.225(a)); Class B and C; within 30 NM of an airport listed in appendix D, section 1, surface to 10,000 feet MSL (Mode C veil); above the ceiling and within the lateral boundaries of Class B or C up to 10,000 feet MSL; Class E in the 48 contiguous states and D.C. at and above 10,000 feet MSL excluding at and below 2,500 feet AGL; and Class E over the Gulf of America at and above 3,000 feet MSL within 12 NM of the U.S. coastline. Transponder/Mode C airspace is in §91.215(b) and largely overlaps. Limited exceptions exist (for example certain aircraft without an engine-driven electrical system — see §91.215(b)(3) and §91.225(e)). Always read the current regulation and the chart; this table is a study aid.
Practice questions
1. What are the requirements to operate in Class B airspace?
Show Answer
ATC clearance, two-way radio, Mode C, and ADS-B Out. Student pilots need a §61.95 endorsement for that specific Class B (ground and flight training plus a logbook endorsement). Student solo at the primary airport also needs that airport listed in the endorsement (§91.131).
2. At what altitude does Class A airspace begin?
Show Answer
Class A airspace begins at 18,000 feet MSL and extends up to and including FL600 (60,000 feet).
3. On a sectional, what depicts Class E airspace beginning at 700 feet AGL?
Show Answer
A magenta vignette (fade). Magenta dashed is Class E to the surface. Blue vignette is typically 1,200 feet AGL. Blue dashed is Class D.
Next
Test your knowledge with the figure written (sectionals) and airspace flashcards.
Sources
- 14 CFR §91.215, §91.225, §91.131, §61.95, §91.155
- AIM Ch. 3; PHAK Ch. 15 (FAA-H-8083-25); Private Pilot ACS (FAA-S-ACS-6)
- 14 CFR §91.215
- 14 CFR §91.225
- FAA Air Traffic Publications (AIM)
- FAA Aviation Handbooks & Manuals (PHAK)
- FAA Airman Certification Standards