Air safety
Safety in unmanned aviation is about keeping risk as low as reasonably practicable, not about eliminating every hazard. A hazard is a potential source of harm (a building, a crowd, a power line, a gusting wind). Risk is the combination of the likelihood of that harm occurring and the severity if it does. Questions often test this distinction: a hazard is not a risk, and a risk assessment must consider both probability and consequence.
Safety thinking uses barriers (planning, checklists, geofencing, visual observers, failsafe settings). The Swiss-cheese model shows that an accident needs holes in several barriers to line up. Just culture encourages reporting of errors and occurrences without fear of punishment, so that lessons are learned. You should know the difference between an accident (death, serious injury, or significant damage), a serious incident, and an incident.
In the open category, assess both air risk (other aircraft) and ground risk (people, property, vehicles). Traps: assuming a small drone is automatically low-risk; ignoring the “uninvolved persons” test; treating a near miss as unimportant.
Rule of thumb: risk = likelihood × severity. If either factor is high, do not fly until you have reduced it.
Worked example: You plan to fly beside a busy road. Hazard: moving vehicles. Likelihood of a loss of control is moderate; severity could be fatal. Combined risk is unacceptable, so move to an open field away from the road rather than relying on the drone’s automation.