Air Force One uses a pilot signal from the coach’s air brake system to deliver 100%, direct proportional braking. No inertia (adjustable) system can match this braking profile, period. Just as you don’t adjust the individual braking effort of each wheel on the coach, you don’t adjust the braking effort of Air Force One. The towed vehicle experiences the same perfect braking symmetry as each individual brake on the coach. As such, the exhaust brake and transmission retarder have no effect on the Air Force One. Only air brake to meet DOT and chassis regulations.