What does it mean if a pilot sees "S" next to a runway on a chart?

When a pilot sees an "S" next to a runway on a chart, it indicates that the runway is soft. This designation is particularly important for pilots as it signals that the runway surface may not provide the ideal amount of support for the aircraft during takeoff or landing. A soft runway could be composed of materials such as grass, dirt, or even a wet surface, which can affect the aircraft's performance, particularly with regard to braking and acceleration.

The presence of this designation prompts pilots to exercise caution and consider their aircraft's weight, speed, and other factors before attempting to land or take off from such a runway. Understanding the condition of the runway is essential for ensuring safety and making informed operational decisions while flying.