What does "VLOS" stand for in UAS operations?

"VLOS" stands for Visual Line of Sight, which is a critical concept in unmanned aircraft systems (UAS) operations. It refers to the requirement that the remote pilot must maintain a visual reference to the drone throughout its flight. This ensures that the pilot can effectively see and control the aircraft to avoid collisions and navigate safely.

Maintaining VLOS is vital for safety and regulatory compliance. By keeping the drone within visual range, the pilot can better assess the environment, monitor the drone's position, and respond promptly to any potential hazards. This requirement is part of the FAA’s regulations for commercial drone operations under Part 107, emphasizing the importance of human oversight in UAS operations.

The other options, while they may sound plausible, do not accurately capture the established definition of VLOS in the context of drone operations. For example, Variable Loss of Signal could imply a technical issue affecting control, while Vertical Limit of Safety and Vessel Line of Sight do not relate to the pilot's visual oversight of the UAS.