Airspace rules and permits
Staying clear of crewed aircraft
The highest-consequence risk in UAV operations, and the one most easily avoided entirely.
#prevention
Airspace rules and permits
Operations and safety
Protecting people around the operating area
People on the ground are the priority, and they usually have no idea there is any risk.
Operations and safety
Handling incidents and lost aircraft
Preparing for the crash, the flyaway and the mid-mission failure that will eventually happen.