During the period from sunset to sunrise, what must a lighter-than-air airship be equipped with?

Lighter-than-air airships must be equipped with position lights in conjunction with an aviation red or white anti-collision light system during the hours from sunset to sunrise. Position lights provide visibility of the airship to other aircraft and ground personnel, indicating its position and orientation. The aviation anti-collision light system enhances safety by alerting nearby aircraft to the presence of the airship, reducing the risk of accidents. The combination of these lighting systems ensures compliance with aviation regulations regarding night operations and minimizes the chances of mid-air collisions. This requirement is critical for ensuring the safety and visibility of lighter-than-air craft during night operations and is a standard practice in the industry.