Uncrewed Systems Technology 047 l Aergility ATLIS l AI focus l Clevon 1 UGV l Geospatial insight l Intergeo 2022 report l AUSA 2022 report I Infinity fuel cell l BeeX A.IKANBILIS l Propellers focus I Phoenix Wings Orca

26 Dossier | Aergility ATLIS maximum flight endurance of 4.5 hours through its MAT and turboprop-hybrid powertrain, all the parts for which are mounted about what is currently a 40 cu ft (1.13 m 3 ) cargo container. Iterative development Between 2015 and 2017, Yonge and Vander Mey carried out some key groundwork. “Just one of the many problems we needed to solve early on was optimising the rotor, not only for low-drag autorotation performance in forward flight, but also reasonable efficiency during hover,” Yonge (now VP of r&d at Aergility) recounts. “Jim would primarily do CFD simulations, while I developed a blade element analysis system that gauged performance while giving insight into mechanical properties. Both of us used X-Plane simulations and considered different aircraft configurations.” In 2018, Aergility was approached by a large (unnamed) organisation which had ascertained that the company’s proposed aircraft was a potential solution to some key use cases in its business. “They wanted to invest in and eventually purchase our future aircraft, on the condition that we could first prove that our solution worked in real-world tests,” Vander Mey says. Aergility had developed a quarter-scale prototype in 2017, which was tested from 2018 to 2020. This was an X-8 coaxial octocopter with a push-propeller, but no wings or cargo hold yet. “Finding suitable e-motors was challenging, but that paled in comparison to motor controllers,” Yonge says. “At the time, most ESCs were geared towards drones running at the top of their motors’ rpm and thrust curves, but we needed fine control over both power and speed, even at near-zero thrust and when the motor was generating electricity. “So initially on the Gen 1 prototype, we just used an open-source ESC that allowed us to do all the changes and tests we wanted. We also built a coaxial motor test stand where we could gauge the motor pairings and ESCs at different states of hover.” Even before the Gen 1, Aergility built its version of an ‘artificial wind tunnel’, which consisted of a structure on the back of a pick-up truck reminiscent of a multi-rotor airframe. Driving the truck down roads near the company simulated the rush of air in flight, and enabled testing of how the rotors and ESCs performed in forward flight and autorotation at different pitch attitudes, ahead of the first test flights in February 2018. December/January 2023 | Uncrewed Systems Technology The company developed its tech using a quarter-scale proof of concept UAV (top, landed; middle, in flight) and then a more refined and efficient iteration, also at quarter-scale (bottom) Aside from its main investor and customer, Aergility anticipates deploying the ATLIS in humanitarian and military resupply missions, and commercial logistics in regions lacking secure rail or road networks On the Gen 1 we just used an open- source ESC that allowed us to do all the changes and tests we wanted. We also built a motor test stand