Class E Airspace (798 feet question)

Class E airspace can be confusing for many people, so we are going to walk you through an example Class E airspace question.

(Refer to FAA-CT-8080-2H, Figure 21, area 1) Find the radio tower that is direct to the south of Minot International Airport (MOT). [Note: The tower is along Interstate 83, with a mean sea level altitude of 2,179 feet.] If you were flying your drone at the maximum altitude above the tower, would you need prior approval from Air Traffic Control?

Step 1: Locate the tower in question

Now that we have located the tower, we can move on to step 2.

Step 2: Determine what type of airspace is surrounding the tower

By zooming in on the map, we can see that the tower in question is inside of Class E airspace, but because it's a shaded magenta line that Class E airspace doesn't start until 700 feet above ground level.

Next, we need to determine how high we can fly our drone above the tower.

Step 3: How high can you fly your drone above the tower?

From looking at the sectional chart, we can tell that the towers height is 2179 feet MSL or 398 feet AGL. Since FAA regulations permit drone flights 400 feet above the tower, you could fly your drone at 798 feet above ground level.

Step 4: Decide if this flight would require airspace authorization.

We know that flying at 798 feet would put us 98 feet inside the Class E airspace, and you may think that you need authorization for this. 

Class E airspace that begins at 700 feet AGL (shaded magenta line), does NOT require airspace authorization. If the Class E airspace started at the surface and was designated for an airport (dashed magenta line), you would need prior authorization.

Therefore, in this scenario you would not need authorization because you are not flying within Class E airspace that starts at the surface and is designated for an airport.

If you'd like to learn more in depth about Class E airspace you can view an FAA presentation about it here: Class E Presentation