The latest tests performed by the University of Dayton Research Institute’s Impact Physics Lab show that even the impact of a small drone, using a DJI Phantom could have severe consequences.
The tests were designed to mimic a midair collision at 238 mph. A 2.1-pound DJI Phantom 2 aerial drone was launched into the wing of a Mooney M20 aircraft.
The video shows that the small drone did not shatter upon impact but tore open the leading edge of the wing. It entered the wing’s structure and damaged the main spar, which researchers say could be a risk to manned aircraft.
Many have questioned the research because firing a small drone at a wing in a lab does not take into account any aerodynamic forces, and the drone had no propellers on it.
However it is stimulating the larger debate and awareness about aircraft collisions with UAV equipment.
Details of the Impact Test using a Small Drone
Here are some relevant extracts from the UDRI article:
“While the quadcopter broke apart, its energy and mass hung together to create significant damage to the wing,” said Kevin Poormon, group leader for impact physics at UDRI.
Poormon, whose group routinely performs sponsored bird-strike testing of aircraft structures—such as wings, windscreens and engines—presented test results and video of the drone shot at the fourth annual Unmanned Systems Academic Summit, held in August at Sinclair College’s Conference Center and its National UAS Training and Certification Center in Dayton.
As the number of hobby drones in the air dramatically increases, so does the risk of a catastrophic event, Poormon said. “We’ve performed bird-strike testing for 40 years, and we’ve seen the kind of damage birds can do. Drones are similar in weight to some birds, and so we’ve watched with growing concern as reports of near collisions have increased, and even more so after the collision last year between an Army Blackhawk helicopter and a hobby drone that the operator flew beyond his line of site.
Although the helicopter returned home with only minor damage to a rotor, Poormon said it is only a matter of time before a drone strike causes more significant damage to a manned aircraft.
“We wanted to help the aviation community and the drone industry understand the dangers that even recreational drones can pose to manned aircraft before a significant event occurs. But there is little to no data about the type of damage UAVs can do, and the information that is available has come only from modeling and simulations,” said Poormon, whose group has fired individual drone batteries, cameras and motors at metal panels. “We knew the only way to really study and understand the problem was to create an actual collision, and we’re fully equipped to do that.”
Poormon and his team collaborated with the Sinclair College National UAS Training and Certification Center, whose experts provided guidance on unmanned aerial systems. “We’re fortunate to be in close proximity to Sinclair’s nationally renowned UAS Center,” Poormon said. “We’re experts on bird strikes, but Sinclair’s team provided valuable insight on how these systems are being used and helped us determine the best models for testing.” In addition, Sinclair provided quadcopters for testing and, because the college also offers a program in airframe aviation maintenance, loaned UDRI an aircraft wing to serve as a target.
After calibration work to ensure they could control the speed, orientation and trajectory of a drone, researchers fired a successful shot at the Mooney wing. The researchers then fired a similarly weighted gel “bird” into a different part of the wing to compare results. “The bird did more apparent damage to the leading edge of the wing, but the Phantom penetrated deeper into the wing and damaged the main spar, which the bird did not do.”
Poormon said additional tests using similar and larger drones on other aerospace structures, such as windscreens and engines, would provide critical information about how catastrophic a collision would be. He and his team are hoping even this first test result will help bring awareness to the manned and unmanned aviation communities about the importance of regulations related to safe drone operating.
UDRI operates the most diversified impact physics laboratory in the world, with 12 gun ranges capable of propelling objects at velocities ranging from tens of feet per second to more than 33,000 feet per second. Researchers routinely perform research and testing in the fields of foreign object damage, light armour design and evaluation, penetration mechanics, hypervelocity impact testing and analysis, and dynamic behavior of materials.