Anti-skid activation occurs at what speed?

• A. 10 kts
• B. 5 kts
• C. 15 kts
• D. 20 kts

Answer: (A)

Anti-skid activation occurs when wheel speed sensors detect a risk of wheel lock during braking on the ground. The system watches wheel RPM and ground speed, and if the slip ratio indicates impending skid, it modulates brake pressure to keep the tire from locking and to maintain steering control. In practice, the activation threshold is about 10 knots of ground speed. At this point, braking is being controlled to prevent a skid as the airplane decelerates after touchdown. Speeds lower than that are generally before the system should engage, while higher speeds would be past the initial protection window, when the system should already be actively modulating. So, 10 knots is the correct activation speed.