Fluidic Thrust Vector Control for the Stabilization of Man/Ejection Seat Systems.

A 2-axis, hydrofluidic thrust vector control TVC system was designed to improve the total trajectory of an ejection seat system during adverse conditions from 0 to 600 knots air speed. A nonlinear model of the seat was derived and linearized to determine the best hardware components for meeting those requirements. A vortex rate sensor, fluidic resistance-capacitance rc compensation and a two stage servovalve, using hot gas pressurized oil were chosen to drive a ball and socket nozzle with 20 degrees of thrust deflection. This system controls seat attitude and rate in the pitch and yaw axes. Of the many operating conditions analysed, the worst case was 70 degrees nose down, -250 degreessec pitch rate, 2 inches cg offset in pitch and cg offset in yaw at 0 knots. Recovery heights of 360 and 100 feet are achieved at 0 and 600 knots with a 5000 lb. rocket burning 0.5 sec. By stabilizing the escape system at its aerodynamics trim condition with the drogue chute out during rocket burn, the remainder of the flight remained stable.