In runway condition codes, RCC 4 describes a surface condition equivalent to what?

• A. DRY
• B. WET
• C. ICE
• D. COMPACTED SNOW with GOOD to MEDIUM braking action

Answer: (D)

RCC describes how the runway surface will affect braking performance, combining surface type with an expected braking action. RCC 4 is the snow category that corresponds to compacted snow with good to medium braking action. This means the surface is snow-covered but compacted enough to provide reasonable friction—better than loose snow or ice, but not as good as dry or wet pavement. In practice, you’d expect a longer stopping distance and more cautious braking than on dry or wet pavement, but not as severe as on ice or very loose snow.

The other options describe different surface conditions: dry implies the highest braking action, wet lowers friction from a film of water, ice indicates very poor braking, and compacted snow with good to medium braking action specifically matches RCC 4.