Canopy Pneumatic Control Module

hydraulically lock the canopy actuator in any position when the canopy pneumatic control module is in the neutral position. Flow regulators control actuator speed by permitting free flow of hydraulic fluid to the actuator and restricted flow from the actuator. Thermal relief valves relieve pressure from the double-acting cylinder to the transfer cylinders. The canopy hydraulic actuator is accessible from the NFO station when the canopy is opened and the NFO ejection seat is removed. Canopy-Lock Pneumatic Actuator The canopy-lock pneumatic actuator locks and unlocks the canopy. It operates with nitrogen pressure from the canopy pneumatic control module and the canopy pneumatic timer. The actuator moves the canopy for- ward or aft to the RETR (locked) or EXT (unlocked) position, respectively. When the ac- tuator piston reaches its full EXT (unlock) travel limit, the timer check valve permits pneumatic pressure flow from the canopy pneumatic control module to the open side of the canopy hydraulic actuator. While the canopy closes, the timer check valve vents pneumatic pressure from the canopy hydraulic actuator through the canopy pneumatic control module. When the canopy-lock pneumatic actuator piston moves toward the RETR (locked) position, the timer check valve reseats. Lock Actuator Restrictors The lock actuator restrictors regulate the speed of the canopy-lock pneumatic actuator during canopy locking and unlocking. Canopy Pneumatic Timer The canopy pneumatic timer permits pneu- matic pressure flow from the canopy pneumatic control module to the lock side, of the canopy- lock pneumatic actuator and vents or pressurizes the canopy hydraulic actuator shutoff valves. The last closing motion of the canopy actuates the timer. Canopy Pneumatic Control Module The canopy pneumatic control module regulates pressure from the canopy pneumatic reservoir and directs it to the canopy pneumatic timer, timer check valve, canopy hydraulic actuator, and canopy-lock pneumatic actuator. The module contains a filter, restrictor, two pressure reducers, two relief valves, low-pressure sensor, and control valves. If canopy pneumatic reservoir pressure drops below 225 psi, the low- pressure sensor causes the module valves to lock the remaining pressure in the canopy hydraulic actuator to counterbalance the weight of the canopy. This allows manual opening and closing of the canopy. Canopy unlocking is accomplished by the auxiliary unlock mode. Canopy Pneumatic Reservoir The reservoir stores high-pressure dry nitrogen for operation of the canopy pneumatic system. The reservoir is serviced to 3,000 psi; it has a 225-cubic-inch capacity. Servicing is accomplished through the pneumatic servicing charging module, which is remote from the reservoir. Reservoir Check Valve The reservoir check valve is in the servicing line to the canopy pneumatic reservoir. The valve prevents nitrogen flow from the reservoir to the pneumatic servicing charging module. Reservoir Relief Valve The reservoir relief valve, on the canopy pneumatic reservoir, prevents overpressurization of the reservoir. The valve opens at 4,500 psi and reseats at 4,100 psi. Pneumatic Servicing Charging Module The pneumatic servicing charging module is in the nosewheel well. This module contains a 2-4