What must a pilot do if they cannot maintain communication with visual observers?

If a pilot is unable to maintain communication with visual observers, it is crucial to cease operations immediately. Communication with visual observers is essential for ensuring safety, particularly in maintaining situational awareness and avoiding potential hazards. The visual observer's role is to assist the pilot in monitoring the drone's surroundings, including recognizing other air traffic, obstacles, and environmental factors that could affect the flight operation.

Without effective communication, the pilot may not receive critical information needed to make informed decisions about the flight. Continuing to operate without supervision could pose significant risks to safety, including potential collisions or other accidents. Hence, stopping the flight until stable communication is reestablished or until a resolution is found is the most responsible course of action to ensure safety for everyone involved.