Skid Control and Recovery
Skid control and recovery - what is tested
The examiner tests whether you can name the type of skid, apply the right correction, and avoid the habits that cause skids in the first place.
What causes skids
- Overbraking, over-accelerating, oversteering, or simply too much speed for the surface.
- A locked wheel loses both traction and steering, which is why the first move in most skids is to get the wheels rolling again.
Recovery basics
- Release the brake or accelerator to let the wheels turn.
- Steer in the direction the rear of the vehicle is sliding - turn toward the skid.
- Look where you want to go, not at what you are about to hit.
- Correct smoothly; a second sharp input starts a new skid the other way.
Skid types
- Drive-wheel skid: the rear of the tractor slides out. Release the accelerator, countersteer, avoid hard braking.
- Front-wheel skid: the vehicle goes straight no matter where you steer. Release brake pressure; the front wheels must roll before they can steer.
- Trailer skid: the trailer swings out of line. Release the trailer brake or hand valve, steer to follow, and reduce speed gradually.
ABS
- ABS stops wheel lockup. Hold firm, steady pressure and never pump the pedal.
- ABS does not shorten every stopping distance and does not fix bad speed choices; a trailer may not be equipped at all.
Worked example
On a wet downgrade a lightly loaded trailer's drive wheels lock during a firm application, and the rear of the tractor steps out to the left. Correct response: release enough brake pressure to get the tires rolling, steer left toward the skid to bring the rear back in line, then reapply the brakes gently and shift to a lower gear. Braking harder or steering right would either prolong the skid or swap it to the other side.
Traps
- Pumping the brakes on an ABS-equipped tractor.
- Braking hard in a curve instead of slowing before it.
- Believing you can steer while the wheels are locked.
- Overcorrecting and triggering a skid the other way.