On May 9, under partly cloudy skies at Travis Air Force Base in California, the military invited an autonomous driving and flying robot to roll into a hangar and deliver a package. The machine, half of Elroy Air’s Chaparral delivery drone, was all exposed wires and metal brackets on four tall stands, and is a testbed for their autonomous driving program. With the demonstration, the Air Force got one step closer to adapting a useful cargo drone for military resupply missions, all without further strain on human pilots.
The Chaparral is a vertical takeoff and landing drone, with a large fixed wing, propellers for vertical thrust, and rotors that can provide vertical lift, enabling it to operate from small landing pads. None of that was present in the demonstration at Travis AFB, which was part of the Golden Phoenix Exercise. Instead, the ground autonomy system was mounted on a freestanding rig, with motors and wheels and sensors to steer around any obstacles it might encounter on a runway. Beneath it, and central to the Chaparral’s function, was a detachable cargo pod.
“One of the things that we showed at the event was our robotic ground tester, what we call ground bot. That demonstrated our autonomous taxing capability as well as our cargo pod pickup and drop off, and our cargo handling capabilities that we would use on the Chaparral,” says Amisah Prakash, director of customer programs at Elroy Air.
Autonomy for delivery on the ground is an important part of the overall vision for the drone, as it keeps the burden on human operators low while ensuring that the goods carried can get where they need to be. A runway is a complex environment, with planes and people and other vehicles moving around, to say nothing of the possibility of animals interloping on some of the more remote environments the drone is expected to operate. Getting the goods from point A to point B without incident is especially important when a runway collision might involve cargo that explodes.
“One of the use cases that we’ve been talking a lot with the Air Force on is logistics resupply types of missions, like, bringing cargo back and forth from different locations, whether that is fuel or munitions, anything that is needed for the ground troops to be able to do what they need to do,” says Prakash.
While shipping munitions is a more uniquely military mission, the Chaparral is intended as a truly dual-use aircraft, with an eye towards the commercial cargo market. As Popular Science reported last year, FedEx was interested in the plane, specifically taking advantage of the cargo pod’s 300-to-500-pound capacity, or about half the weight of what a typical delivery truck can carry. The drone will be able to deliver this at a range of up to 300 miles, and do so while flying faster than 100 mph.
If the comparison point for ground transport is a delivery truck, for remote delivery to small military bases a good point of comparison is a helicopter. During the US war in Afghanistan, both crewed and autonomous helicopters would deliver supplies to forward operating bases, austere outposts located where the fighting was and far from regular access to supplies.
Imagine, says Clint Cope, chief product officer and co-founder for Elroy Air, that a mission commander is trying to send supplies somewhere, and triaging what is the most important use for an aircraft. “That decision-making gets a lot simpler when you can send a cheaper, in some ways expendable air asset, when you’re using an uncrewed system,” he says.
Cope offers as a comparison point a single helicopter making one supply run with 5,000 pounds of cargo. If that helicopter is shot down, it’s all lost in one go, and in order to make the mission, that full 5,000 pounds of load has to be assembled before any of it can go out for delivery. “You can go and load up a Chaparral [drone] and send a much smaller, almost right-sized amount of supplies where they’re needed and be able to have that much more rapid turnaround,” says Cope.
In that way, using the drones changes resupply from fewer, higher-stakes missions, to more of managing a logistics flow through drones.
The Chaparral runs on jet fuel, like much of the Air Force, and has a generator to power its electric motors. It still needs human refueling, but the drone’s design, especially the pivot on its wing, is made so it can be transported inside larger cargo aircraft, like a C-130 or C-5, and flown from almost anywhere.
While autonomous driving is useful for getting between the runway and the hangar, the loading ramp of a cargo plane is not a place to risk automated driving.
“We demonstrated how you can manually remote control the vehicle as well,” says Matt Michini, director of robotics at Elroy Air. “So if somebody on the ground wants to taxi it into a hangar or they want to move it to move it outta the way so that a plane can drive by or something, we want it to demonstrate how that’s possible as well without too much rigamarole.”