What does the "braking action" reports refer to?

The concept of "braking action" reports is essential in assessing runway conditions, specifically regarding how effectively an aircraft can decelerate on a given runway surface. These reports provide pilots and air traffic controllers with critical information about the friction between the aircraft's wheels and the runway, which can be influenced by various factors such as weather conditions, runway materials, and surface contaminants like snow, ice, or water.

The information in these reports helps pilots make informed decisions about landing and takeoff procedures. For instance, if the braking action is reported to be poor due to icy conditions, a pilot might opt for a longer runway or adjust their approach and landing technique to account for the decreased stopping capability. This knowledge is vital for ensuring safety during operations in varying runway conditions.