What is the proper order for the steps of coupling a tractor to a trailer?

Proper coupling procedure: (1) Inspect the area and trailer; (2) Make sure the trailer wheels are chocked or the trailer brakes are set; (3) Inspect the fifth wheel — clean, greased, jaws open, slide locked; (4) Position the tractor directly in front of the trailer (do not back under at an angle); (5) Back slowly until the fifth wheel just touches the trailer; (6) Connect and supply air to the trailer to check brake function and lines; (7) Back under firmly to engage the kingpin in the jaws of the fifth wheel; (8) Pull forward gently against the kingpin to verify the trailer is securely coupled; (9) Visually inspect the connection — kingpin fully seated, locking jaws closed; (10) Connect electrical and air lines; (11) Raise the landing gear; (12) Remove chocks. Skipping or reordering steps causes drop-offs, blown air lines, and broken kingpins.