Abstract: A method for controlling an aircraft to prevent high G-caused pilot unconsciousness. Data defining a state space of acceleration, rate of change of acceleration and duration of acceleration at maximum acceleration within which an aircraft may be operated without causing pilot unconsciousness is provided to an aircraft intelligent flight control system. The flight control system continuously monitors the past and present state of the aircraft and compares to the surface boundaries of the defined safe state space, Whenever the aircraft exceeds those boundaries, the flight control system intervenes to unload the aircraft to within those boundaries. Additional data and measurements may be added to define an n-dimensional state space. Another embodiment unloads the aircraft to a baseline acceleration. A simplified embodiment is described which compares current acceleration to a preselected value of acceleration.

Abstract: A novel anti-G suit valve system is disclosed which provides very rapid response to imminent high acceleration. The disclosed embodiments of the new valve system can be retrofitted to existing mechanical anti-G valves to create a hybrid valve system capable of achieving the desired qualities of fast triggering of the valve in response to imminent acceleration and maximum rate inflation of the anti-G suit. The new valve system measures acceleration and, by differentiation, the rate of change of acceleration. When both acceleration and rate of change of acceleration exceed preselected values, a solenoid mounted in place of the press-to-test button on a mechanical anti-G valve is energized for a preselected period of time to fully depress the valve spindle, providing maximum rate delivery of pressurized air. The hybrid valve reverts to normal operation at the end of the preselected period of time.