Position and Warning Systems Which of the following functions does a skid control system perform? 1. Normal skid control. 2. Normal braking. 3. Fail safe protection. 4. Locked wheel skid control. 5. Touchdown protection. 6. Takeoff protection. a. 1, 2, 3, 4. b. 1, 3, 4, 5. c. 1, 2, 5, 6.