What condition requires a UAS operator to notify the FAA?

Notification to the FAA is required in the event of an accident involving serious injury or property damage. The FAA defines serious injury as any injury that requires hospitalization or results in a loss of consciousness, and significant property damage is typically considered any damage exceeding a certain monetary threshold. This requirement is essential for the FAA to assess the safety of UAS operations and investigate incidents that could have implications for aviation safety.

In this context, reporting is not mandated for minor injuries or accidents resulting in little to no damage, as these do not significantly affect the overall safety framework. While malfunctions of the UAS are critical to be aware of, they do not always necessitate FAA notification unless they result in an accident that meets the FAA's criteria. Unauthorized flights in controlled airspace do raise serious safety concerns and regulatory violations but typically do not require a formal accident report unless they lead to an incident causing serious injury or property damage. Thus, of all the scenarios provided, the requirement to notify the FAA aligns explicitly with serious injuries or significant property damage, making it the correct answer.