How to tell Class E to the surface from Class G on a sectional chart
On a sectional chart, a dashed magenta line around an airport marks Class E that starts at the surface, so you need ATC authorization, usually through LAANC, before you cross it. A shaded magenta band marks Class E with a floor at 700 feet AGL. Below that floor you're in Class G, so at 400 feet or lower you need no authorization. Class B, C and D also need it.
From the lesson Airspace Authorization and Operating Near Airports
Why it matters on the exam
Airspace questions on the Part 107 test often hand you a sectional chart figure and ask whether a flight needs ATC authorization. The answer depends on where the controlled airspace floor sits compared with your altitude, and the line style is how you read that floor. Mixing up the dashed magenta line and the shaded magenta band is one of the easiest ways to lose a point.
Key points
- Dashed magenta is your fence. A dashed magenta line around an airport marks Class E designated to the surface. Crossing it needs prior ATC authorization, usually through LAANC.
- Shaded magenta means 700 feet. Under a shaded magenta band, Class E begins at 700 feet AGL. Below it is Class G, so at your 400-foot limit you need no authorization.
- B, C and D always ask first. Solid blue marks Class B, solid magenta marks Class C, and dashed blue marks Class D. Each reaches the surface around its airport, so each needs authorization.
- The floor matters, not the letter. Class E only needs authorization inside an airport's surface area. Where its floor is at 700 or 1,200 feet, you fly in the Class G beneath it.
- Class G still has rules. No authorization does not mean no limits. You stay at or below 400 feet, keep the drone in sight, give way to crewed aircraft, and never interfere with traffic at any airport, heliport or seaplane base.
Sort these airspaces and chart symbols by whether your drone needs ATC authorization at 400 feet or below
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Drag each card into its box, or tap a card and then a box.
Common trap
Many candidates see "Class E" on the chart and assume they need authorization, or they treat the shaded magenta band as the boundary. The shaded band only tells you Class E starts at 700 feet, so you are in Class G beneath it. The dashed magenta line is the one that means ask first.
Question 1 of 5
You plan a Part 107 flight at 350 feet AGL. You take off under a shaded magenta band, outside any other boundary, and your route then crosses a dashed magenta line around a small airport. When do you need ATC authorization?
Tap an answer and I’ll tell you why.
Question 1 is written for this page and checked by a person. The others are practice questions from the MindMax app. None are from a past exam.
Where it comes from
Lesson 3 in Operating Limitations · Regulations (UA.I)
Airspace Authorization and Operating Near Airports
- Identify the airspace where ATC authorization is required (Class B, C, D and lateral limits of Class E surface areas for an airport)
- State that no authorization is needed for Class G or for Class E above the surface area
- Apply the rule against interfering with operations and traffic patterns at any airport, heliport or seaplane base
- State that an authorization's conditions must be followed exactly
Key terms in this lesson
- LAANC
- The system, usually used through an app, for requesting ATC authorization to fly in controlled airspace such as Class B, C, D or surface Class E around an airport.
Learn more
FAQ
A dashed magenta line marks Class E airspace that starts at the surface around an airport, and you need ATC authorization to fly inside it. A shaded magenta band marks Class E with a floor at 700 feet AGL. Below that floor is Class G, so a drone at 400 feet or lower needs no authorization there.
Class B generally runs from the surface to 10,000 feet MSL around the busiest airports, built in two or more layers like an upside-down wedding cake. Class C generally runs from the surface to 4,000 feet above the airport elevation, usually with a 5 NM surface area and a 10 NM outer circle from 1,200 to 4,000 feet above the airport. Both need ATC authorization for your drone.
No ATC authorization is needed in Class G, even near a small airport with no tower. You still must not interfere with operations and traffic patterns at any airport, heliport or seaplane base. Find the approach paths and keep your drone well clear, because crewed aircraft always have the right of way.