The behavior of sUAS under explosive loading conditions and implications for safe operating procedures

Drones are increasingly being used for tasks previously unimagined and the beneficial uses are evolving. The United States Congress has envisioned the possible uses of drones for both combating and conveying explosive threats and other harmful and destructive activities. Congress\u27 intent is reflected in new laws (2018) and policies (2019). All civilian available Small Unmanned Aerial Systems sUASs (Drones), weighing less than 55 pounds, in the current market are not designed for operations in explosive environments. This first of a kind research focuses on further understanding of sUASs response to explosive loading and the public policy implications. This research measured and observed effects on a drone in flight at different heights away from the detonation of 0.5 lbs of C4 explosive. Based upon experimental research it has been determined that the cross section of the propeller material of a sUAS -- the key component that keeps the drone aloft -- is the weakest component withstanding explosive detonations; electronic magnetic impulse (EMP) from C4 charges was not sufficient to disrupt the flight, and the semiconductor components did not experience failures due to very short (microseconds) high temperatures. In all, the sUAV tested was found to be very robust. A theoretical mathematical model showing the relationship between the distance from the blast and the peak reflective pressure experienced by the drone is provided. Simple rules of thumb for safe standoff heights for survival of sUAS, and minimal flight disruption during an explosion event beneath for various weights of C-4 are provided --Abstract, page iii