Demco 9599019 Air Force One Supplemental Brake System . Towed vehicle brake control for air brake motorhomes. includes wireless coach link. Air Force One (AFO) is the only supplemental braking system that features the necessary components to meet Total Coach Protection safety regulations. With no moving parts to wear out, your AFO will stand the test of time. It is the only air brake system that energizes the towed vehicle’s power brakes through a patented process that doesn’t require an electronic vacuum pump. It uses a pilot signal from the coach's air brake system to deliver 100 Percent direct proportional braking. And in the event of a separation of the coach and towed vehicle, AFO is the first and only supplemental brake system that seals the coach’s air supply.