[nynor]

Originally Posted by Rick V

The natural resting position for air brakes is full lock, the application of air causes them to release. When you step on the brake pedal you remove the air from the brakes and they apply. So the only way to lose brakes is if the foot valve fails. The parking brake is a completely separate function of the rear brakes, it has a pull/push knob that either removes or applies air to the rear brakes. If that is pulled the rear brakes will lock up, and bloody fast. The driver never applied the parking brake, it is impossible for a total system failure.

oy, not good. and the NTSB is on it? why are they being asses with you all?