The plane which is defined by the head-to-foot and anterior-to-posterior directions in the human body. A stack of images acquired in the sagittal plane separates images by their left-to-right locations. The mid-line sagittal plane bisects the left and right half of the human body.
Under heavy braking, the rear tires lock up and the axle begins to bounce; the amplitude of the bounce becomes so severe that the tires finally develop enough traction (when slamming hard against the pavement) to rip the whole axle assembly free of the vehicle.
Check the truck and trailer combination brakes. NOTE: If the tractor protection valve does not work right, an air hose or trailer brake leak could drain all the air from the tractor. This would cause the emergency brakes to come on, with possible loss of control. heavily loaded vehicle will take a long distance to stop because the spring brakes do not work on all axles. Lightly loaded vehicles or vehicles on slippery roads may skid out of control when you apply spring brakes. It is much safer to stop while the tanks have sufficient air to use the foot brake.