How is a displaced threshold identified on a runway?

A displaced threshold is identified on a runway by a solid red line across the runway. This marking indicates that the area beyond the red line is not available for landing, although it may be used for takeoff. The purpose of a displaced threshold is often to enhance operational safety by allowing aircraft to use a portion of the runway for takeoff while designating another portion specifically for landing.

The solid red line serves as a clear visual cue for pilots to understand that they should not land after this line, reinforcing the need to utilize the designated landing area prior to the threshold. This marking is important for maintaining safe operations, particularly in scenarios where obstacles or other limiting factors may restrict a direct approach to the runway.

In contrast, the other options involve different markings that serve distinct purposes. A double red line is typically used to indicate a no-entry zone, while a solid yellow line is often seen in taxiway marking indicating an area where aircraft should not enter. Dashed white lines signify movement areas, like those on taxiways. Recognizing these different markings is crucial for airport operations and overall safety in aviation.