Tips from the FAA’s drone pioneer

Read the rest of our coverage from May’s special report on drones.

Jim Williams took over the FAA’s Unmanned Aircraft Systems (UAS) Integration Office one month after Congress directed the agency to write rules to allow drones to fly in U.S. airspace within four years. Although many drone developers were frustrated by the slow pace of the FAA’s regulatory process, people who worked closely with Williams give him credit for helping to draft regulations that have opened U.S. skies to hundreds of thousands of drones that weigh less than 55 pounds, flying within view of their operators and below 400 feet.

Q: A lot has happened in last year or two.

You can say that again.

Q: What has to happen to integrate unmanned aircraft into the national airspace?

I would argue they are already being integrated as we speak. FAA rules that came out last summer started the process. At low altitude, you have commercial and personal drones flying all the time. There have been a lot of reported sightings of drones where maybe they shouldn’t be. That is, I think a little bit overblown, because pilots are notorious for not identifying objects very well. And I think a lot of the sightings will never be validated because there is no way to validate them. Drones don’t show up on radar. But the good news is we have not had any reported collisions or any reported accidents where drones have caused serious injury or collisions with aircraft. That’s the good news. Even with the proliferation, we are still maintaining an excellent safety record. So there is already integration happening at lower altitudes in uncontrolled airspace but more and more aircraft are being approved to fly near airports for commercial operations by the FAA. There’s a whole bunch approved to fly at night. It’s really moving forward.

Q: What has to happen for drones to operate beyond line of sight?

The big impediment there is that the aircraft are going to have to be approved. The initial rules the FAA came up with essentially mitigated any potential problems with the aircraft by restricting when and how they can be flown. The FAA’s assumption is that at any point in time that aircraft could stop working and fall out of the sky, so you need to have operating rules that protect against that. As soon as you want to fly over people or you want to fly beyond visual line of sight, the FAA’s position is the aircraft has to be approved. There are a whole bunch of ways to get the aircraft approved, but the bottom line at this point is the only ones that have been approved are some military surplus aircraft. Those were approved while I was at the FAA and they are still operating in various functions. They are very restricted to where they can go. In fact, their approval is called restricted category aircraft.

The big barrier that everybody is waiting to see is that first commercial aircraft approved. There’s a company called AeroVironment that builds the Puma and the Raven and the Wasp for the militaries around the world. The FAA publicly announced they have agreed on a certification basis for their aircraft to get design approval. That was a huge step forward. Now it’s up to the folks at AeroVironment to demonstrate they meet those rules they negotiated with the FAA. They are in the process of doing that. Once that happens, things are going to start to open up. It still remains to be seen what sort of limitations are going to be placed on that aircraft once it’s approved. I assume it’s going to be approved for flying over people and flying beyond visual line of sight, at least in remote areas. When that happens, I think you are really going to see applications.

Q: Like what?

There are thousands of miles of linear infrastructure, everything from rail lines to pipelines to power lines. Regulations require those to be inspected. You could do it with a Puma. Right now, a lot of them use rotorcraft to do that. The railroads actually use trucks with people in them on the rails to do their inspection. They have to shut the rail lines down while they are inspecting them. There seems to be a lot of interest and a lot of companies investigating it but until they get an approved aircraft, they can’t get moving forward. That is the biggest impediment at this point. The initial standards that can be used to approve these aircraft are out there. Things are starting to fall into place. In the next couple of years, I think you will start to see beyond visual line-of-sight applications in remote areas.

Q: Are there technologies that still need to be developed, like sense and avoid?

Sense and avoid has been developed, demonstrated and approved. The problem is that the initial technology, like so many initial technologies, are fairly crude and very expensive. The one NASA demonstrated last year requires a pretty large aircraft because it uses military grade phased array radars to detect the aircraft in the environment and feed that information back to the pilot so they can avoid them. There are other technologies that are being explored and eventually they will be certified. This is typical of how the aviation industry works. Things are developed in the military and proven out in the military and they migrate their way into the civil market as the cost comes down and the availability comes up. That’s the same situation we have with detect and avoid.

There are a lot of people out there experimenting with different solutions, everything from LIDAR [light detection and ranging] to acoustic sensors and stereoscopic visual. That’s what Intel has demonstrated. They sent one of their quadcopter drones to a forest and told it to fly to the other side. It found its way through the forest without running into anything using stereoscopic vision. Then there’s the radar solution the military and NASA developed. What is happening is the natural evolution of technology is going to take the need and turn it into systems that can be deployed on multiple size aircraft. The technology is proprietary so I don’t know what it is but AeroVironment, as part of their certification, is going to have some form of detect and avoid on their aircraft. That is a key piece. The technology is there, but getting a system that can be approved by the FAA is really the next step.

Q: Is detect and avoid a better term than sense and avoid?

Detect and avoid is the term being used internationally in aviation.

Q: Are there issues with command links?

The real problem is not creating a link. It’s creating a link the FAA would approve for beyond visual line of sight. The current crop of drones use bands that are available for public use. Like Wi-Fi. Both the 2.4 and 5 gigahertz signals that are out there are being used for the commercial off-the-shelf visual line-of- sight-type aircraft. The problem with those links is they are limited in range and the range is not deterministic. The way these systems work — since everyone is transmitting on the same frequency and there is no deconfliction of the signals — they all transit at once and try to rely on the fact that everything is a little bit different in distance apart and so therefore the signals arrive at different times. That works when there are not too many transmitters. But as soon as you get a stadium full of people or an outdoor concert and everyone has their cellphones on with their Wi-Fi transmitters going, all of the sudden that interference goes up. So your range will go down. That makes the range of the signals nondeterministic, which is something the FAA doesn’t like. If you are going to depend on that link to help you avoid collisions, you have to depend on that link to the level that you would be able to assure that you would be able to avoid a collision if one arose as you were flying the aircraft. There are solutions cropping up out there that are not commercially available but will be shortly. There is some work going on in satellite and terrestrial systems, but they are not all out there and deployed yet. Again, that will depend upon you having a customer, people who invest in putting the systems out there to allow them to communicate. The technological solutions are resolved, but the implementations of the solutions and getting approval by the FAA are the challenges being worked on now.

Q: It sounds like once things are developed and approved, it will take time for them to become small and inexpensive enough for widespread adoption.

Initially the approvals will be fairly conservative. They will be remote areas. They will be of limited duration. But as the experience grows and the systems mature, the FAA will expand the approvals. That’s always the way it’s gone with aviation in general. It used to be you couldn’t fly over the ocean with only two engines. You had to be within 100 miles of an airport with only two engines. Now there are airplanes flying four or five hours from the nearest airport with only two engines. As the technologies are validated and demonstrated to the FAA, they get more and more permissive with the use of them.