Drones are not allowed to fly over and near groups of people for safety reasons, hopefully every drone pilot knows this by now. But what exactly happens when a drone crashes on a human being? Is it fatal, are there serious injuries or “only” a few painful cuts?
These questions have been investigated by the Alliance for System Safety of FAS through Research Excellence (ASSURE) in a unique 18-month study. The “Phase II Soil Collision Study” analyzed possible head injuries caused by collisions with common consumer drones. The aim of the study was to find out how to design drones more safely to minimize serious injuries.
The Dangers of a Drone Collision
The results of the study may surprise you: Even though the videos of the impact look quite dramatic, the researchers found that the plastic drones were rather flexible and elastic. Drones such as the DJI Phantom and Mavic Pro actually absorb a significant amount of impact energy.
The most common injuries in collisions with the head were lacerations, cuts and bruises. However, the severity of possible concussions is not easy to assess and needs to be further investigated. The ASSURE researchers also observed severe eye injuries caused by the propellers. One of the recommendations from ASSURE therefore is to use propeller guards.
The study also shows that the payload poses a great danger to the drone, because unlike the plastic drone frame, it is usually very rigid and inflexible and cannot absorb the impact energy. This is especially the case when the payload is attached outside of the drone.
For example, a battery that is placed on the outside of the drone poses a greater risk of injury than one that is completely integrated into the drone.
It is likely that in the future there will be regulations on what payloads will be allowed on a drone and how it needs to be integrated. Drone parachute systems (for example ParaZero or Indemnis) can significantly reduce the risk of injury, but many more tests under better controlled conditions are required to make more accurate statements.
The researchers also stated that sometimes only a minimal change of impact angle had a huge impact on the severity if the injuries. Further test and investigation are required to validate the study’s results.
The First Study to Assess Risk of Injuries Caused by Drones
The ASSURE study was the first really comprehensive study on head injuries caused by drones. 512 impact tests were conducted using 16 different types of unmanned aircraft, including popular consumer drones such as the DJI Phantom and Mavic Pro. The researchers also used various kinds of payloads (batteries, woodblocks) with weights ranging from 0.71 to 13.2 lbs.
In addition to investigating the risks of injury from a drone crash, the study also aimed to develop a methodology for safety testing and to make recommendations to the US Federal Aviation Administration (FAA).
You can read the full report of the ASSURE study here.