Ejection seat with pitch, roll and yaw control

DETAILED DESCRIPTION An object of the present invention is to provide an aircraft ejection seat having pitch, roll, and yaw control.
Ejection seats without such control are hazardous to use because rotations cause the parachute to be difficult or impossible to deploy, sometimes resulting in parachute failure.
The present invention provides an aircraft ejection seat having two gimballed rocket motors which may be attached either below or behind the seat.
A control circuit causes the gimballed rocket motors to rotate in response to pitch and yaw command signals.
A pitch command signal alone causes both gimballed rocket motors to have identical angular displacements so that the thrust vectors from the gimballed rocket motors are always parallel.
A yaw command signal, either alone or combined with a pitch command signal, causes the gimballed rocket motors to have different angular displacements; and the non-parallel thrust vectors cause a torque about the yaw axis of the ejection seat.
The gimballed rocket motors are moved by servo-controlled hydraulic actuators connected between the rocket motor housings and the frame of the ejection seat.
A yaw rate signal is processed by a computer to determine the yaw angle of the seat.
Yaw rate and yaw angle signals are combined by a summer to produce a negative yaw feedback signal which is connected to the input of the control system.