What is the minimum visibility required while flying during twilight?

The minimum visibility required while flying during twilight is 3 statute miles. This standard is established to ensure that a pilot operating a small unmanned aircraft can maintain visual line of sight with the drone and be able to navigate and avoid obstacles effectively. Twilight conditions can reduce visibility due to the transition from daylight to darkness, so having a clear visibility requirement helps enhance safety. The 3 statute miles threshold strikes a balance between allowing operations under less than optimal lighting conditions while ensuring that the pilot can manage the risks associated with flying during such times.

Choosing a standard higher than this could limit operational opportunities for drone pilots during twilight. In contrast, having a standard lower than 3 statute miles may compromise safety as it could reduce the pilot's ability to see and navigate effectively. Thus, the regulation is designed with safety and operational feasibility in mind.