A propeller blade angle control circuit, comprising: a propeller pitch change mechanism; an oil cooling line; a fixed-displacement pump located upstream of the propeller pitch change mechanism and adapted to provide a supply of oil from an engine oil return system to the propeller pitch change mechanism; and a valve (30; 130) disposed between the pump and the propeller pitch change mechanism, the valve (30; 130) having a valve body (31; 131) with a cavity (35; 135) therein, the valve body (31; 131) including an inlet port (32; 132) fluidly communicating with the pump, an outlet port (33; 133B) configured for fluid communication with the engine oil return system via the oil cooling line, and a single pitch port (34; 134) fluidly communicating with the propeller pitch change mechanism, the valve (30; 130) including a spool (36; 136) within the cavity (35; 135) displaceable between a first position and a second position within the valve body (31; 131), wherein in the first position, the spool (36; 136) permits communication through the outlet port (33; 133B) to the oil cooling line, in the second position the spool (36; 136) blocks the outlet port (33; 133B) to permit oil to flow through the single pitch port (34; 134) to the propeller pitch change mechanism, the spool (36; 136) is in the first position during steady-state operation of the propeller pitch change mechanism, the spool (36; 136) is in the second position during transient operation of the propeller pitch change mechanism, and the spool (36; 136) is displaceable within the cavity (35; 135) to always leave the single pitch port (34, 134) at least partially unblocked and always direct oil toward the propeller pitch change mechanism. a propeller pitch change mechanism; an oil cooling line; a fixed-displacement pump located upstream of the propeller pitch change mechanism and adapted to provide a supply of oil from an engine oil return system to the propeller pitch change mechanism; and a valve (30; 130) disposed between the pump and the propeller pitch change mechanism, the valve (30; 130) having a valve body (31; 131) with a cavity (35; 135) therein, the valve body (31; 131) including an inlet port (32; 132) fluidly communicating with the pump, an outlet port (33; 133B) configured for fluid communication with the engine oil return system via the oil cooling line, and a single pitch port (34; 134) fluidly communicating with the propeller pitch change mechanism, the valve (30; 130) including a spool (36; 136) within the cavity (35; 135) displaceable between a first position and a second position within the valve body (31; 131), wherein in the first position, the spool (36; 136) permits communication through the outlet port (33; 133B) to the oil cooling line, in the second position the spool (36; 136) blocks the outlet port (33; 133B) to permit oil to flow through the single pitch port (34; 134) to the propeller pitch change mechanism, the spool (36; 136) is in the first position during steady-state operation of the propeller pitch change mechanism, the spool (36; 136) is in the second position during transient operation of the propeller pitch change mechanism, and the spool (36; 136) is displaceable within the cavity (35; 135) to always leave the single pitch port (34, 134) at least partially unblocked and always direct oil toward the propeller pitch change mechanism.