Drones that collide with large manned aircraft can cause more damage than similar sized birds, according to new research released by the FAA yesterday. Conducted by the Alliance for System Safety of UAS through Research Excellence (Assure), the study was released in advance of a House aviation subcommittee hearing today on how emerging uses of unmanned aircraft systems are changing the national airspace system.
Assure’s research is designed to help operational and collision risk mitigation requirements for drones, the FAA said.
“While the effects of bird impacts on airplanes are well documented, little is known about the effects of more rigid and higher mass [small unmanned aircraft systems] on aircraft structures and propulsion systems,” said Mississippi State University’s Marty Rogers, director of Assure. “The results of this work are critical to the safety of commercial air travel here in the U.S. and around the world.”
The research involved both computer modeling and physical validation testing. Researchers modeled impacts of 2.7-pound and four-pound quadcopters, along with four-pound and eight-pound fixed-wing drones on a single-aisle commercial airliner such as a Boeing 737 and a Learjet 30/40/50. The study explored potential impacts of several areas: the wing leading edge, windshield, and vertical and horizontal stabilizers. “The windshields generally sustained the least damage and the horizontal stabilizers suffered the most serious damage,” the FAA said.
Structural damage ranged from little to no impact to penetration of the drone into the airframe. The research did not assess risk to flight that may result from the damage. Researchers, however, “concluded that unmanned aircraft system manufacturers should adopt ‘detect and avoid’ or ‘geo-fencing’ capabilities to reduce the probability of collisions with other aircraft,” the agency added.
Future research is planned for engine ingestion and additional collision studies involving helicopters and general aviation aircraft.
Assure used resources from Mississippi State University, Montana State University, Ohio State University and Wichita State University in its study.
House aviation subcommittee chairman Frank LoBiondo (R-New Jersey) said in his prepared statement for today’s hearing that the research results thus far are "concerning” and that “We will monitor the future of this research closely as they investigate the risks of ingestion of UAS into jet engines.”
Noting that two million drones have been sold in the U.S. to date, LoBiondo added that “the sheer volume of UAS…and their unique features are causing policy-makers and operators to rethink all aspects of airspace use.”