Which visual cue is least helpful during a night flight?

During a night flight, visual cues play a significant role in navigation and situational awareness. Cloud reflections are the least helpful visual cue compared to the others. This is primarily because cloud reflections tend to obscure landmarks, terrain, and other visual cues that are essential for orientation and navigation.

While stars, ground lighting, and moon visibility can provide useful references for pilots—stars for navigation and orientation, ground lighting for identifying features and obstacles on the ground, and the moon can provide ambient illumination—the reflections on clouds do not offer reliable information. Instead, they can create misleading visual impressions and can contribute to disorientation, making it difficult for pilots to gauge altitude and ground proximity accurately.

Thus, while the other options provide valuable information that can enhance a pilot's awareness and assist with navigation during a night flight, cloud reflections do not serve this purpose effectively.