How to read a sectional chart for the Part 107 test
Airspace lines, altitude figures, obstacles and airport data on a sectional, decoded in plain English for the Part 107 test and for real jobs.
The first time you open a sectional chart, it looks like someone spilled blue and magenta ink over a road map. That’s normal, and it’s also the part of the test where a lot of study time goes. Chart questions hand you a figure and ask you to find one fact on it: an airspace floor, a tower height, a radio frequency. Those figures come from the testing supplement, FAA-CT-8080-2H, which the test center gives you. From October 26, 2026 the test also adds image questions taken from current VFR sectional charts.
This guide reads a sectional the way a chart question does, one symbol at a time. Our reference is the FAA’s Aeronautical Chart Users’ Guide (effective July 9, 2026).
It’s worth learning properly, not just for the test. Say a roofer asks you to shoot a house on the edge of town. Before you say yes, you’ll check a sectional to see what airspace sits over that roof and whether you need permission to fly there. It’s the same skill, used on a real job.
What you have at the desk
The test center supplies the supplement, scratch paper and a writing instrument, and it may also offer a basic calculator, a flight computer and transparent overlays. You may bring your own plotter, straightedge, protractor or non-electronic magnifying glass. The proctor makes the final call on what’s allowed.
We’d bring a magnifier. Chart figures are dense, and a tower height in small print is easy to misread.
Three conventions before any symbol
Unless the chart marks something otherwise, distances are nautical miles, altitudes are feet MSL (above mean sea level), and times are UTC. Part 107’s 400-foot limit, though, is AGL (above ground level). Forgetting to convert between the two is one of the easiest ways to lose a chart question.
A sectional is drawn at 1:500,000, so one inch is 6.86 nautical miles, or about 8 statute miles. Lines of latitude run east and west and measure degrees north or south of the equator. Lines of longitude run pole to pole and measure degrees east or west of the Prime Meridian. The contiguous U.S. sits between 25° and 49° N and between 67° and 125° W.
Supplement questions can point you to a numbered “area” on the figure, the way the FAA’s sample questions do. Find that area first, then read only the symbols near it.
Airspace symbols
This table is the heart of chart reading. The last column tells you what each symbol means for an actual Part 107 flight.
| On the chart | What it is | For a Part 107 flight |
|---|---|---|
| Solid blue altitude figures, ceiling over floor | Class B | ATC authorization required |
| Solid magenta altitude figures, ceiling over floor | Class C | ATC authorization required |
| Dashed blue line | Class D | ATC authorization required |
| Dashed magenta line | Class E surface area for an airport | ATC authorization required |
| Magenta vignette (fuzzy shaded band) | Class E starting 700 ft AGL | Class G below the floor unless other airspace is charted |
| Blue vignette | Class E floor other than 700 ft, next to Class G | Class G lies beside it |
| Solid magenta line, 30 NM | Mode C required airspace around Class B | Not a Class B boundary |
Class E exists from 1,200 feet AGL unless the chart shows otherwise, and the Class G below it is uncontrolled. Class A starts at 18,000 feet and isn’t drawn on visual charts, so it sits far above anything you’ll fly.
Reading altitude figures
For Class B and Class C, each sector shows its MSL ceiling and floor with the last two zeros dropped. A Class C shelf marked 40 over 12 runs from 1,200 to 4,000 feet MSL. SFC as the floor means the sector starts at the surface.
Two special cases come up often enough to learn:
- A ceiling of T in Class C means the Class C rises to, but not including, the floor of the Class B above it.
- A Class D ceiling with a minus sign, such as -25, means from the surface up to, but not including, 2,500 feet MSL.
Converting to AGL
The conversion is where most of the points are. Subtract the ground elevation from the MSL figure.
Say you plan to fly at 400 feet AGL under a Class C shelf with a floor of 1,200 feet MSL, and the ground there is 900 feet MSL. The shelf floor is only 300 feet above you (1,200 minus 900). At 400 feet AGL you’d be inside Class C, so you’d need authorization.
Over lower ground, the same shelf sits higher above you. With terrain at 500 feet MSL, the floor is 700 feet AGL, and a 400-foot flight stays below it. Always convert using the ground elevation at your site, not the airport’s.
Airports and their data
Airports with a control tower, and their data, are printed in blue. All other airports are magenta. The data block gives the airport elevation (the highest point of the usable landing area), the longest runway length in hundreds of feet, and frequencies. A symbol after a frequency marks it as the CTAF (the common traffic advisory frequency pilots use to announce themselves), and a star means that service is part time.
The ACS (the FAA’s list of what the test covers) expects you to know how to use a CTAF to monitor manned traffic, and the FAA’s own sample question asks for the CTAF at an airport on a figure.
A magenta airport inside Class G needs no ATC authorization. You still have to stay out of its traffic pattern and approach paths, and you can’t interfere with its operations.
Obstacles and terrain
Sectionals typically show man-made obstacles taller than 200 feet AGL. Each one shows the height of its top in feet MSL, with its height above the ground in parentheses below when that’s known. So “1249 (320)” is a structure 320 feet tall whose top is 1,249 feet MSL. UC means under construction. In crowded areas, a group obstacle symbol shows only the tallest one.
That number in parentheses matters on inspection work, because of the structure exception in Part 107. Within 400 feet of that 320-foot tower, you could fly up to 720 feet AGL.
The Chart Users’ Guide also warns that wind turbine blade tips aren’t lit, and that the lights on the hub can in some cases sit 200 to 300 feet below the tip.
The Maximum Elevation Figure (MEF) is the large number printed in each quadrant bounded by the 30-minute latitude and longitude ticks. It shows the highest terrain or obstacle in that quadrant, rounded up to the nearest 100 feet, with the last two digits left off. An MEF of 35 means 3,500 feet MSL.
Special use airspace and routes
| Marking | Meaning |
|---|---|
| P- plus number | Prohibited area |
| R- plus number | Restricted area |
| W- plus number | Warning area, from 3 NM off the coast outward |
| Name plus “MOA” | Military operations area |
| A- plus number | Alert area |
| VR or IR plus four digits | Military training route with no segment above 1,500 ft AGL |
| VR or IR plus three or fewer digits | Military training route with a segment above 1,500 ft AGL |
To fly in a prohibited or restricted area, Part 107 requires permission from the agency that uses or controls it. You also have to follow NOTAM flight restrictions, including TFRs (temporary flight restrictions). A TFR is itself a type of NOTAM, and only national security TFRs are printed on the chart. So a clean chart never proves an area is clear on the day of your shoot, and you still need to check NOTAMs.
A method for chart questions
- Find the named area on the figure and circle it on your scratch paper.
- Identify the airspace by line style and color before reading any number.
- Note whether each figure is MSL or AGL, then convert.
- Apply the Part 107 rule the question is testing.
Airspace carries 20% of the test under PSI’s current weighting, and chart reading shows up inside that area and inside operations too. Keep drilling figures until you run those four steps without thinking about them.
Practice where it counts
The fastest way to find out whether charts have clicked is to answer chart questions under time pressure. Take the free 20-question practice test, which gives you a score by area, and look at your airspace result. If charts are the weak spot, Liftoff’s Chart Lab has 40+ chart questions on the FAA testing supplement figures, and every answer cites its FAA or eCFR source. It’s $49 once with lifetime access, and you can see what’s included.
For the rules behind each airspace class, read airspace classes and when you need LAANC. For the chart questions arriving on October 26, read what changes on the Part 107 test. And if you’re still working out whether the license is for you, start with how to become a drone pilot or check whether you need a drone license.
For how people who passed spread their study time across charts and everything else, see Part 107 test tips from people who passed.