What does the 'Runway Threshold Bar' signify?

The 'Runway Threshold Bar' is an important visual aid that represents the beginning of the landing area of a runway. It is typically marked by a series of white lights or a solid line that indicates to pilots where the actual landing surface starts. When approaching the runway for landing, recognizing this threshold is crucial for ensuring that the aircraft aligns correctly with the runway as it descends.

This marking helps pilots gauge their altitude and distance from the runway during the final stages of approach, contributing to a safe landing. It differentiates the zone where landing is sanctioned, as opposed to other segments of the runway that might not be suitable for landing maneuvers. Understanding the significance of the threshold bar enhances a pilot’s situational awareness during critical phases of flight.