What is the primary reason for ensuring all lights are checked before a night flight?

The primary reason for ensuring all lights are checked before a night flight is to confirm they are functioning properly. This is critical for safety, as operational lights are essential for visibility and communication with other aircraft. For example, navigation lights ensure that other pilots can see your position, orientation, and direction, which helps prevent mid-air collisions. Additionally, landing lights are crucial during approach and landing to enhance the pilot's visibility of the runway and surrounding area.

While checking brightness may be important, the main focus is on functionality—lights that are burned out or malfunctioning can create dangerous situations. Properly functioning lights are key to maintaining situational awareness and complying with aviation regulations. This safety aspect surpasses any considerations of aesthetics or impressing passengers, as these factors do not contribute to operational safety. Thus, confirming that all lights are functioning properly is paramount before embarking on a night flight.