Studies have abounded theorizing about the results of a direct drone hit to a passenger aircraft. Conclusions have estimated the threat level of a drone collision at anywhere from “minimal” to “catastrophic.” Now the FAA has released the results of the study performed by the Alliance for System Safety of UAS through Research Excellence (ASSURE) and the official conclusion is… it depends.
“Although the Federal Aviation Administration (FAA) is not yet able to definitively address these concerns, studies by a consortium of leading universities, through the Alliance for System Safety of UAS through Research Excellence (ASSURE), have begun to bring better understanding to the physical damage associated with small unmanned aircraft – or drones – colliding midair with commercial and business aircraft,” says the FAA press release.
“While the effects of bird impacts on airplanes are well documented, little is known about the effects of more rigid and higher mass sUAS on aircraft structures and propulsion systems,” said Mississippi State University’s Marty Rogers, the Director of ASSURE. “The results of this work are critical to the safety of commercial air travel here in the United States and around the world.”
Researchers used simulations to estimate the damage caused if a typical “commercial narrow-body air transport” (they used a Boeing B737 and an Airbus A320 aircraft as examples) or a “business jet” (a Learjet 30/40/50) collided with either a small quadcopter or a light fixed-winged unmanned aircraft.
Researchers also performed engine impact simulations on the fan section of an existing business-jet-sized, turbofan-engine model – showing what would happen if a drone flew straight into the engine of a plane.
“Computer simulations, supported by material and component level testing, were conducted to determine the effects of sUAS impacts on manned aircraft,” said Gerardo Olivares, Ph.D., Director, Crash Dynamics and Computational Mechanics Laboratories at Wichita State University. “Conducting this study through full-scale physical tests would not have been possible from a cost and time perspective due to the immense complexity of the task. On the other hand, simulation enabled us to study over 180 impact scenarios in a twelve-month period. To ensure results accurately predict the actual physical behavior of collisions, we have spent a lot of time developing, verifying, and validating detailed models of manned and unmanned aircraft. Once the models are validated, we can use them in the future to investigate other impact scenarios.”
The results showed what most researchers already knew – that the effects of a collision would vary based upon the size, weight and density of the drone and the speed of the aircraft. Smaller drones and lower speeds result in smaller potential damage. While somewhat inconclusive, the official study results do pave the way for standards such as already exist for airplanes to protect from bird strikes, and provide a basis for regulatory decisions.
“The findings above show the importance of properly researching and regulating the use of sUAS in a crowed national airspace system. While design features can decrease the severity of a drone impact, sUAS pilots and the public must be aware of and abide by regulations for safe sUAS operations,” says the press release. “It is critical that everything be done to keep these collisions from occurring through the safe separation of all aircraft, both manned and unmanned. The FAA will depend on the sUAS community to help develop the technology for proper detect-and-avoid so that these aircraft do not meet in flight.”
The FAA and ASSURE will continue their testing of various scenarios through FY 2021.