Sectional charts show airspace with colors and line styles: solid blue for Class B, solid magenta for Class C, dashed blue for Class D, and dashed magenta for Class E that starts at the surface. Altitudes on the chart are in feet above mean sea level (MSL), so you subtract the ground elevation to get height above ground. Learn those patterns, plus how airports and obstacles are shown, and you can answer most chart questions on the Part 107 test.
Airspace on the chart
| What you see | What it means |
|---|---|
| Solid blue lines with altitude labels | Class B. Each shelf has a floor and ceiling, like "100/SFC" or "100/40". |
| Solid magenta lines | Class C. Usually an inner circle from the surface and an outer shelf. |
| Dashed blue line around an airport | Class D, with its ceiling in a dashed box, such as [25]. |
| Dashed magenta line | Class E starting at the surface. |
| Faded magenta band | Class E with a floor of 700 ft above ground, on the shaded side. |
| Faded blue band | Class E with a floor of 1,200 ft above ground, on the shaded side. |
| Blue hatched borders | Restricted, prohibited or warning areas. |
| Magenta hatched borders | Military operations areas (MOAs) and alert areas. |
Reading floors and ceilings
Class B and C labels are written as ceiling over floor, in hundreds of feet MSL. "70/SFC" means from the surface up to 7,000 ft MSL. "70/30" means from 3,000 to 7,000 ft MSL. A Class D number like [32] in a dashed box means the ceiling is 3,200 ft MSL, and a minus sign before it means "up to but not including."
To turn MSL into AGL, find the field elevation in the airport data or the terrain around you and subtract. Many test questions are just this subtraction.
The faded bands mark where Class E begins above the ground: 700 ft inside a magenta band, 1,200 ft along a blue band. Below those floors the airspace is Class G, so a drone at 400 ft there doesn't need authorization unless it's also inside B, C, D or surface E.
Airport information
Next to each airport is a block of data:
- Name and identifier, such as the airport code.
- CT with a frequency: the control tower. A star next to it means the tower is part-time.
- Field elevation in feet MSL, lighting, and longest runway in hundreds of feet.
- CTAF (a C in a circle): the common traffic advisory frequency used at non-towered airports.
- UNICOM and ATIS frequencies.
Airport symbols are blue for towered airports and magenta for non-towered ones.
Obstacles
Towers and other obstructions show two numbers: the bold figure is the top in feet MSL, and the figure in parentheses is the height above ground. Groups of obstacles have their own symbol, and lit ones have little lightning marks. The large numbers in each quadrangle are maximum elevation figures (MEFs), the highest terrain or obstacle in that area, in thousands and hundreds of feet MSL.
Airport signs (also on the test)
- Red signs with white text: mandatory instructions, such as runway holding positions.
- Black signs with yellow text: location, telling you which taxiway or runway you're on.
- Yellow signs with black text: direction and destination.
How this shows up in real flying
Apps like Aloft and B4UFLY do the airspace math for you, and LAANC grids show allowed altitudes in feet AGL. The test still expects chart reading, and it helps you understand why an app says what it says. See flying in controlled airspace.
Study tips
- Practice with the FAA's Airman Knowledge Testing Supplement, the same booklet you'll get at the test center.
- Use the chart legend inside the sectional. Everything on the test is in it.
- Do the MSL to AGL math on paper every time.
Rules current as of October 2026. This is general information, not legal advice.
Keep going with the Part 107 study guide and Part 107 practice test.
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