Abstract: A vehicle drive system includes a gas turbine engine having a compressor inlet control to reduce total engine air flow to between two and three percent of normal air flow during periods where fuel flow to the gas turbine engine combustor is terminated. An auxiliary flywheel is mounted between a power turbine output shaft and engine reduction gear for power transfer to the rear differential of a road vehicle. The auxiliary flywheel is driven at high speed of rotation of the power shaft to store energy which is used to start the engine following off modes of operation wherein air flow to the compressor is severely restricted and fuel flow to the combustor is terminated.

Abstract: A gas turbine engine includes a compressor having a plurality of fixed diffuser passages therein each including a gate and associated cam ring control means for operating each of the gates either open or closed to vary the gas flow through the compressor diffuser for turbine engine control; the gas turbine engine further includes a turbine section having a plurality of turbine nozzle passages each having a separate gate therein selectively operated under the control of cam ring means to vary the amount of motive fluid to the turbine in accordance with desired engine operation and wherein each of the gates are operative with respect to either the diffuser or the nozzle passages to change the area of gas flow therethrough by blocking some or all of the channels without resultant change in incident angle of the gas flow with respect to the inlet of each of the passages.