Abstract: An in-flight starting mechanism for a gas turbine engine in a propeller type aircraft propulsion system wherein the propeller is driven by a free power turbine rotor rotatable independently of the gasifier rotor of the engine. The starting mechanism includes an inner race, an outer race and a plurality of rollers in pockets in the outer race. The rollers are centrifugally biased out of engagement with an inner race surface of the inner race when both the free power and gasifier rotors are driven normally in the forward or propelling direction. The pockets are evenly spaced around the inner race so that at least some of the rollers are moved by gravity against the inner race surface when the rotors are substantially stopped as occurs when the engine is shutdown in flight and the propeller feathered.

Abstract: A bleed valve for a compressor wherein compressor discharge pressure is proportional to compressor rotor speed, the bleed valve including a bleed control poppet valve, a pair of differential pressure diaphragms, a pressure regulator valve, and an accumulator. The bleed valve automatically effects bleed air flow in proportion to the rate of acceleration of the compressor rotor when the rate of compressor rotor acceleration exceeds a scheduled maximum rate and for a predetermined duration after the onset of compressor rotor deceleration at a rate above a minimum scheduled rate.

Abstract: An improved fuel control system for a turboshaft gas turbine engine wherein fuel is metered in proportion to the magnitude of a control pressure and a governor operates in a first mode to regulate compressor discharge pressure down to the control pressure and in a second mode causes the control pressure to increase toward compressor discharge pressure at a relatively rapid rate, the improvement residing in the provision of a valve and an accumulator which operate during the second governor mode to retard the rate of increase of the control pressure toward compressor discharge pressure so that compressor instability is avoided even if the engine is accelerated before internal temperature stability is achieved.