Yes, Drone Pilots Must Worry About Manned Aircraft Under 400 Feet AGL

In recent conversations with other drone experts, I’m stunned by the lack of awareness or understanding about drone pilots and the risk of collision with other aircraft because of poor assumptions.

Drone pilots don’t own the airspace below 400 feet above ground level. You have no right of way ownership when you are legally flying.

As a UAS pilot, you must have a 360-degree field of view to take action to avoid other aircraft. Drones are the lowest on the list of aircraft with the primary right-of-way.

If you are flying over any coastal area, open land, parkland, or any location you think is sparsely populated, you may have a manned aircraft operating below 400 feet AGL in complete compliance with the aviation regulations.

Aircraft, both helicopters, airplanes, powered parachutes, weight-shift-control aircraft, and silent balloons, may legally operate much lower than you assume.

The regulation that controls this is 14 CFR § 91.119 Minimum safe altitudes.

91.119(c) is the most crucial regulation to understand.

“(c) Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.”

But if none of those limitations exist, they can operate lower than 500 feet AGL.

At the 3:20 point in this video you can see how an airplane might be operating legally just above the surface.

Yes, Drone Pilots Must Worry About Manned Aircraft Under 400 Feet Agl

Here are a couple of real examples to ponder about.

Water Area

In the video above, as the airplane is flying low above the brackish water area and beach, a drone pilot is operating in the area. The UAS pilot LZ is on land to the left, and maybe a bit back from the water in the trees to remain on dry land.

The airplane is approaching downwind, and the RPIC never hears the aircraft. The drone is flying out over the swampy area, looking for a missing boater, and target-focused on his flying, not thinking of other aircraft or looking around.

The UAS pilot is in big trouble here. The drone must yield the right of way to all other aircraft. See 14 CFR § 107.37 Operation near aircraft; right-of-way rules.

Additionally, the UAS must not pass “over, under, or ahead of it unless well clear.” Who knows what “well clear” means but it must be at a distance that does not lead to an incident.

Between the trees potentially blocking the RPIC view, the wind reducing the sound of the approaching aircraft, and the surprise of an aircraft operating below 400′ AGL, a collision could occur.

If the airplane pilot spotted the drone at the last moment and took evasive action, it could result in a crash of the manned aircraft and loss of life.

In the case where drones and aircraft have collided, the drone pilots have violated several FAA regulation violations and have been found responsible for the violation.

Not only can this result in steep FAA fines, but you should expect to be personally sued by the other pilot, as well as your department and local government.

Wooded Area

A missing person call comes out for someone lost in a wooded area. The drone begins a search out over the trees, outside the VLOS of the RPIC in violation of 14 CFR § 107.31 Visual line of sight aircraft operation.

A manned search aircraft coming into the sparsely populated area where no people, structure, vessel, or vehicle has been observed may be operating lower than 400′ AGL when searching. I’ve been on calls just like this myself.

This is especially true of helicopters slowly flying low and searching. The trees around the RPIC can muffle the sound of the approaching aircraft and make it hard to determine where the aircraft is.

The UAS pilot violates several regulations and is increasing the risk of a collision. The drone pilot must land the drone immediately and not fly while aircraft are in the area.

Why This is Important

I’m in the process of obtaining my seaplane rating for search and rescue flying, and part of that training is educating seaplane pilots that they can operate below 500′ AGL in certain areas. But, of course, we have to when landing or taking off on the water. But consider the need to fly low when conducting a missing person search over a large lake.

Right or wrong, drone awareness is not part of that training. Drone pilots have the ultimate responsibility to operate their aircraft following the rules that regulate drone operation. Drones do not have the right of way and must remain clear of other aircraft.

Until some point in the future when the rules might change, that’s the way it is.

How to Avoid Conflight and Collissions

Every single UAS flight must and should comply with the following requirements at a minimum:

  1. Be able to see the drone in compliance with 107.31. The flight distance in most cases is only between 600 to 1,200 feet, depending on if the pilot looked away from the aircraft or environmental factors reduce visibility. For more on this see this post.
  2. Have a 360-degree view of your functional area so you would be able to take action to yield the airspace to any aircraft entering the area. You don’t have much time. A helicopter can chew up 56 yards a second as it approaches you. You must be ready to bring the drone down immediately where it is.

Night Makes No Difference

These rules also apply at night. The entire reason you are required to fly with anti-collision lights (ACLs) at night is to provide some visibility to manned aircraft. However, just because you have ACLs on your UAS does not give you additional privileges. All the above still applies.