ON a bright, sunny afternoon in Wiltshire on July 9, a white, unmanned air vehicle (UAV), its two, 2.75-horsepower engines buzzing, taxied smoothly down a finely mowed field of dark-green grass. It lifted off and effortlessly soared to an altitude of 325 feet.
After 10 minutes, the drone, which has a wingspan of 13 feet, gently returned. It was the second of its 20 short test-flights that day. For the first 14, the drone was controlled remotely by a pilot on the ground. The last six were on autopilot, run from a laptop. Small UAVs are a frequent sight in the low altitudes of UK airspace, but this drone was a rare bird because most of its key parts, including the fuselage and fuel tank, were fashioned in lightweight nylon by a 3-D printer.
Three years ago, University of Southampton researchers, led by Jim Scanlan, a professor of aerospace design, scored a world first when they built and flew a UAV constructed from parts made by additive manufacturing, or 3-D printing. That first UAV was smaller, with a four-foot wingspan. Since then, Scanlan’s team, armed with a €4.4m government grant, has proved that drones can be built and tested in two weeks using 3-D printing. Now, Scanlan has set his sights on a bigger target. He wants to prove that the 52-pound, 3-D-printed drone that swooped over the wheat fields of Wilshire in July is a prototype for next-generation cargo planes. “I strongly believe that all cargo aircraft will soon be unmanned,” he says.
Scanlan also says that large cargo planes, assembled from 3-D-printed parts, will soon be plying the skies using inexpensive, off-the-shelf communications technologies, instead of the expensive sense-and-avoid systems the aviation industry is testing.
That’s a view at odds with the industry and its regulatory agencies. A spokesman for Britain’s Civil Aviation Authority said no large drones will be permitted to fly in UK airspace until they’re equipped with avoidance technology. “It won’t happen until there’s a reliable system,” he says.
To prove otherwise, Scanlan has started a programme, HIATUS (Highlands and Islands Aerial Transport Using Unmanned Systems), which, he hopes, will, within 18 months, use 3-D-printed drones (each about half the size of a small Cessna plane and flying semi-autonomously) to ferry goods to remote islands in Europe that have poor transportation links and are often inaccessible because of fog and bad weather. “Our unmanned aircraft,” he says, “is perfectly happy flying in fog.”
Over the past decade, the US military’s drone fleet has grown from less than 5% of all aircraft to 40%. Militaries have been the biggest developers and users of UAVs. But that’s about to change. In September, 2015, the US Federal Aviation Administration will introduce regulations allowing for UAVs in civil airspace, and it predicts 10,000 drones will be flying in American skies by 2017.
A 2012 report, by US-based aviation consultants, Teal Group, estimated that by 2022 annual spending on UAVs would jump from €5bn to €8.6bn. Initially, small UAVs are likely to be used for border surveillance, policing, monitoring sea-lanes and inspecting farmlands.
But the economic impact will come once large cargo carriers go pilotless. The cargo industry is eager to cut fuel costs and reduce its carbon footprint by using lighter, more efficient planes. That’s why drones could be welcome. Planes without humans don’t need expensive, heavy life-support systems to keep cabins pressurised. UAVs also take pilot pay out of the equation.
The researchers running the Autonomous Systems Technology Related Airborne Evaluation and Assessment (or ASTRAEA) project — a three-year, €125m effort, jointly funded by industry and government that’s researching how best to allow UAVs and manned aircraft to share the UK’s airspace — agree.
Last summer, ASTRAEA carried out test flights across Britain using a two-engine, Jetstream prop plane that was remotely controlled from the ground (although an onboard human pilot handled the take-offs and landings). The problem isn’t having robotic planes in controlled airspace, says Lambert Dopping-Hepenstal, ASTRAEA’s project director, but flying in the low-altitude, “uncontrolled airspace” on the edge of an airfield. “It is more difficult in uncontrolled airspace, where anyone can fly — balloonists, gliders, parachutists — [and] where we now depend on pilot response. You can’t put a UAV in that airspace until you prove it is safe.” So there’s a big push to develop avoidance systems. Dopping-Hepenstal says that’s a technical challenge, though solvable by 2020.
Scanlan says that “the regulators have got it wrong.” Avoidance systems are still far from ready, “and they’re a waste of time and too complicated.” They’re cameras, Scanlan says, but cameras don’t work in clouds or fog, “so what’s the use of that?” He says all commercial planes use transponder-passive radar systems that enable them to ‘talk’ to each other and avoid collisions in clouds. “Transponders work,” he says. The better option is to require other types of craft, like balloons and gliders, to be fitted with transponders. Scanlan’s HIATUS project uses transponder technology on its drones, with a system it calls “airspace multiplexing”. This means operating its UAVs during low-demand night hours and in poor weather, to reduce the chances they’ll encounter other craft.
Scanlan says that once he has a small fleet of 3-D-printed drones flying safely without sense-and-avoid systems, he’ll convince regulators he’s right and win approval to fly larger, unmanned cargo jets in more populous areas. “The most convincing argument you can put to regulators is, ‘We’ve done 1,000 to 5,000 hours without incident,” he says.