The weather’s still pretty good as I write—though we’ve had a few cloudy days, and winter rain, fog and ice are just a couple of months away. Nonetheless, I’ve been spending more time on the ground than in the air lately.
I’ve spent some of it thinking about the changes we’re going to see in the air in the next few years, and the most worrying of those changes will be sharing the air with robots—unmanned aerial vehicles (UAVs), remotely piloted aircraft (RPVs), in a word: drones.
It’s already happened on a limited basis. Until recently there was a TFR over Beale Air Force Base due to operation of the Air Force’s Global Hawk RPV. It wasn’t all that restrictive—Beale is Class C airspace, so two-way radio contact is already required. The TFR added a requirement to have an operating transponder before entering the airspace. That assured ATC could track all aircraft in the area and provide separation between civil aircraft and the robots.
TFRs are one of two ways that the FAA deals with drones in the United States’ airspace today. The other is a Certificate of Authorization or Waiver (COA), which is issued for operations of drones in a limited area. The COA typically requires the use of human spotters, either on the ground or on a chase aircraft, who watch out for traffic and warn the drone operator.
The FAA is under pressure to find a less restrictive way for robots to share the air with manned aircraft. Creating a TFR every time a drone will be flying obviously isn’t practical, and requiring human spotters to observe every drone is a very expensive proposition.
Based on military experience, drone operations aren’t nearly as cheap as proponents suggest. Military drones usually have a crew of two: a pilot and a sensor operator, and those two are backed up by a small army of maintainers and planners.
That’s part of the reason Beale’s TFR has gone away. The Global Hawk turned out to be so expensive to operate that the Air Force switched back to the manned (and more than half a century old) U-2 for most strategic reconnaissance missions.
Nonetheless, as a proponent of drone technology told me a few years ago, the vision of removing human pilots from every “dirty, boring and dangerous” flying job has a lot of people excited—and they’ve got the attention of the U.S. Congress, which directed the FAA a couple of years ago to find a way to integrate drones into the U.S. national airspace.
Some missions for civil drones have such big benefits that they’re hard to argue with. In California this year, we had a terrible fire season—more fires than I can count, the worst of which (the Rim Fire) burned more than 400,000 square miles, much of it adjacent to, and some of it in Yosemite National Park.
To help characterize the fire, the California Air National Guard sent an MQ-1 Predator drone, from Victorville in Southern California, over the fire—more than 200 nm north. According to press reports, the route was mainly over uninhabited areas, but looking at the charts, much of it was probably uncontrolled airspace.
A good friend of mine recently attended a presentation by one of the pilots involved in that mission. According to him, there had been a significant effort to coordinate with ATC along the route. Things went fine in Southern California airspace—and as I’ve already noted the Northern California folks ought to be familiar with drones, since they flew out of Beale for several years—but apparently communications broke down at the boundary.
After being handed off to a NorCal controller, the MQ-1 pilots were given a call: “Traffic, three o’clock.”
Being good airmen, both the pilot and sensor operator turned their heads 90 degrees to the right—and found themselves staring at the brick wall in their control office.
A little later they were asked, “What kind of aircraft is an MQ-1?” to which came the one-word response: “Drone.”
That’s part of the problem we face sharing the sky with robots—ATC and others, including pilots, are going to have to understand the capabilities and limitations of drones. It doesn’t do any good to tell a drone pilot there’s traffic at 3 o’clock. While high-end drones carry cameras that can see much further than the human eye, they’re designed to image targets below the drone.
The solution most commonly talked about for this problem is “sense and avoid”—keeping clear of traffic moves from the Mark-I eyeball to other means, and that’s where ADS-B comes into the story.
By 2020, every vehicle in U.S. controlled airspace (manned or robot) is supposed to broadcast its position by radio. That will enable ATC to track everybody—and also mean that the robots will be able to sense when other aircraft are present, and maneuver to avoid us.
I can offer some personal experience at this point. I’ve tested a wide range of receive-only portable ADS-B equipment. In a nutshell: don’t buy. Unless you are transmitting—and the receive-only equipment can’t—you’re going to get an incomplete view of the traffic around you. In my considered opinion, that’s worse than useless.
With that said, just about one month ago, I had a chance to test a portable ADS-B setup that both receives and transmits and had a completely different experience. While the equipment was a pain to install (and effectively turned my four-seat single into a two-seater, at best), it worked like a champ.
As long as I flew within a line of sight of the FAA’s network of ADS-B ground stations, I could reliably expect the system not only to send my position to every other nearby airplane, but also to alert me of nearby traffic, which showed up on my iPad. I’m here to tell you it was pretty impressive. It showed me traffic that I could not find on my own.
Now, what does that have to do with robots? Imagine a drone flying where I was. With ADS-B working (and assuming all aircraft were properly equipped) the drone operator is aware of all aircraft in their vicinity. When ATC calls, “Traffic, three o’clock,” the operator checks a screen and replies, “Traffic detected.”
This all sounds fine, and should work well—provided every aircraft, manned or robotic—is equipped with ADS-B. But there’s a catch: the FAA’s mandate requires equipage by 2020 if you want to fly in controlled airspace. It’s not required for flight in uncontrolled (Class G) airspace. The boundary between controlled and uncontrolled airspace worries me.
Years ago in Texas I spent a week flying right-seat in a twin used as an executive transport for a cardiologist flying between medical clinics. One of those flights was particularly memorable. There was a cloud layer, and we’d flown over it VFR-on-top, then got an instrument approach to duck down under and land.
The approach went fine, but when we popped out, we found ourselves looking at a crop duster coming from the other direction. He wasn’t quite on a collision course, but it got my attention.
The duster was operating legally, as he had good visibility under the layer and the ceiling was high enough for him to maintain VFR cloud separation. But he either didn’t have a radio or if he did, he certainly wasn’t using it. We had no idea he was there—and he didn’t know about us—until we were far too close for comfort.
I bring this up, because aerial application is frequently mentioned as an appropriate mission for civil drones. But if that’s going to happen anywhere near airports, those drones had better be equipped with ADS-B or some other capability to automatically sense other aircraft. Even a ground spotter would be problematic—no spotter can look in all directions all the time.
The robots I’ve mentioned up to now are all about as large and heavy as a manned aircraft, and therefore present a significant collision risk. There are also smaller flying robots closer in size to model airplanes. I’m less concerned about those—an impact would be more like a bird strike than anything else, and do a lot more damage to the robot than to an airplane—and I expect they’ll be operating only at very low altitudes, outside controlled airspace.
But there again you have the problem: what if someone operating a mini-drone (a police officer using it for surveillance against a suspect, for example) flies into the path of a crop duster (robotic or manned) all in uncontrolled airspace?
John D. Ruley is an instrument-rated pilot and freelance writer. He holds a master’s degree from the University of North Dakota Space Studies program (space.edu). Until recently he was a volunteer pilot with ligainternational.org and angelflight.org, two charities which operate medical missions in northwest Mexico and provide medical patient transport, respectively. Send questions or comments to editor@www.piperflyer.com.
