What is the proper procedure for an emergency stop using air brakes if the vehicle does NOT have ABS?

For an emergency stop WITHOUT ABS, use either: CONTROLLED BRAKING — apply the brakes as hard as possible WITHOUT locking the wheels (locked wheels skid and you lose steering); or STAB BRAKING — apply the brakes fully, and when the wheels LOCK UP, RELEASE the brakes (until the wheels start rolling again), then reapply (repeat). CDL air brakes. The goal is to stop quickly while keeping the wheels ROLLING enough to maintain STEERING CONTROL (rolling wheels can steer; locked/skidding wheels cannot). NEVER just lock up the brakes and hold (causes a skid/loss of control) or take your foot off entirely. WITH ABS, simply apply firm steady pressure (the ABS prevents lockup automatically). Knowing emergency braking techniques (controlled or stab braking without ABS) is commonly tested.