What type of lights are runway end lights?

Runway end lights are designed to assist pilots in identifying the ends of the runway, providing crucial information especially during approaches and landings, particularly in low visibility situations. The correct option describes these lights as fixed unidirectional lights that show red when viewed from the direction of the runway.

This red color indicates to pilots that they are approaching the end of the runway, thus serving as a warning not to continue landing or taking off in that direction. The use of red lights in this context is standardized within international aviation regulations, allowing pilots to make informed decisions based on visual cues.

In contrast, other types of lights mentioned in the incorrect options do not align with the specific functions of runway end lights. For instance, white lights are typically used along runway edges and for taxiways, serving a different purpose altogether in terms of runway orientation and marking. Variable colors are not utilized for runway end lights, as consistency in signaling is essential for safety and clarity.