A blade pitch control assembly comprising a pitch control actuator (1) having a coarse actuator chamber having a coarse chamber area and a fine actuator chamber having a fine chamber area, the coarse chamber area being biased to a feather position, and a primary pitch control valve (2) configured to control the flow of pressurised fluid to the coarse actuator chamber and the fine actuator chamber, respectively via a coarse fluid line and a fine fluid line; the assembly further comprising a hydraulic protection system located between the actuator and the primary pitch control valve, configured to bypass the primary pitch actuator in response to a trigger; wherein the hydraulic protection system comprises a hydraulic protection system valve located between the coarse fluid line and the fine fluid line, wherein activation of the hydraulic protection system valve fluidly connects the coarse fluid line and the fine fluid line so as to balance fluid pressure between the coarse chamber and the fine chamber.
BLADE PITCH CONTROL
COMMANDE DE PAS DE PALE
2022-08-23
Patent
Electronic Resource
English
IPC: | B64C AEROPLANES , Flugzeuge |