Multi-mission​ 3D-printed vehicle from Cummings Aerospace demonstrates Technology Readiness Level (TRL​) 7

On a remote test range in Oregon in January, the cold weather and winds were hard to ignore as engineers prepared for a series of critical flight tests. The weather, however, also served as a reminder of why they were there: to test a much-needed capability that would benefit Soldiers across a number of battlefield conditions. Still, everyone appreciated that Hellhound – the turbojet-powered, 3D-printed drone they were testing wouldn’t keep them waiting out in the cold long. The test itself was going to be fast. Really, really fast.

“Hellhound reached 384 miles per hour,” said Sheila Cummings, founder and CEO of Cummings Aerospace, headquartered in Huntsville, Alabama. “What this means for Soldiers is Hellhound can be downrange and loitering over a target area while quadcopters and propeller drones are still puttering along behind friendly lines.”

During the three-test series the Hellhound drone successfully completed all primary test objectives. During one test, Hellhound flew 20 km, and still had half its fuel remaining. The success of the flights also validated Hellhound’s airframe and subsystems​ are Technical Readiness Level 7, a DOD definition that means the system has proven reliable performance in operationally realistic conditions.

Building upon 12 previously successful flight tests that established the system’s core capabilities, the recent tests also showcased how the drone’s multi-mission​ and modular design could help solve a number of challenges for U.S. armed forces and allies, regardless of the weather.

“Our soldiers operate in environments where the weather could be well below 0°F or well above 100°F, so the more we can test in those extremes, the more we can demonstrate that Hellhound would provide them with a reliable, effective system,” said Cummings. “It’s good to test in cold environments, even if the test engineers would prefer a nice sunny day.”

Proving mission flexibility with modular payloads

Cummings Aerospace conducted its flight tests at the Pendleton Unmanned Aircraft System range, one of the nation’s leading testing and development centers. However, because it takes a lot of space to test a drone that can go nearly half the speed of sound, engineers had to get creative with their flight plans.

“Hellhound is unique in that it launches out of its launch canister vertically using only its engine power,” said Cummings. “And we typically had to fly in something like a figure eight pattern or in large circles in order to stay within the approved area of the test range.”

Specifically engineered to meet the U.S. Army’s Low-Altitude Stalking and Strike Ordnance (LASSO) program requirements to provide Infantry Brigade Combat Teams (IBCTs) the same lethality as an Armored Brigade, Hellhound has a modular payload design. This means service members can swap out the drone’s payload in less than two minutes without tools, whether it’s an explosive warhead, an Electronic Warfare package or an advanced ISR-sensor.

“We correlated our range predictions in our simulations and software with actual flight test data,” said Cummings. “We have a great engineering team and they’re very good at what they do. I had great confidence in their predictions about the system, and the thing that I think surprised them is how good their predictions were.”