Which aircraft lights must be illuminated at night to comply with regulations?

To comply with regulations during nighttime operations, navigation lights must be illuminated. Navigation lights are essential for indicating the position and orientation of the aircraft to other pilots and ground personnel. These lights consist of red and green lights on the wingtips (the left wing has a red light, and the right wing has a green light) and a white light on the tail. They help in ensuring that the aircraft is visible in the dark and assist in avoiding mid-air collisions by clearly defining the aircraft's heading and direction.

While landing lights and strobe lights enhance visibility and can be required during specific operations, they are not mandated for all nighttime flights. Taxi lights are used for ground operations when taxiing but are not required for compliance with regulations regarding visibility in flight. Thus, for regulatory compliance at night, illuminating the navigation lights is essential.