What term is used to indicate bad or no braking action on an airport surface?

• A. BAD
• B. ZERO
• C. POOR
• D. NIL

Answer: (D)

Braking action on a runway is described in four standard levels to tell pilots how effectively they can slow down. The term that signals bad or no braking action is nil. Nil means there is no braking action at all—the surface provides essentially zero friction, so deceleration cannot be achieved with normal braking. This is the formal descriptor used to indicate the surface is extremely braking-restricted. Poor describes some braking, but reduced; good and fair indicate progressively better braking action. Terms like bad or zero aren’t the standard aviation descriptors for braking action, so nil is the official term used in this context.