Auxiliary Unlock Pneumatic Release Valve

filler valve, filter, two check valves, and two pressure gauges. The filler valve allows filling both the canopy pneumatic reservoir and the emergency landing gear reservoir from a single point. The check valves prevent reverse flow when one reservoir has a lower pressure than the other. Canopy Switch The canopy switch is actuated by the canopy locking mechanism lock lockpin; the switch closes when the canopy unlocks. This completes a circuit to the canopy caution indicator light on the pilot and NFO CAUTION ADVISORY indicators. When the canopy locks, the switch opens. Auxiliary Pneumatic Reservoir The auxiliary pneumatic reservoir, aft of the canopy, has a 14.6-cubic-inch capacity. It stores high-pressure dry nitrogen for un- locking the canopy in the auxiliary mode. The reservoir is serviced, through a filler manifold, to 3,000 psi. Auxiliary Pneumatic Reservoir Filler Manifold The auxiliary pneumatic reservoir filler manifold is connected to the auxiliary pneumatic reservoir. It consists of a nitrogen filler valve and pressure gauge. Auxiliary Pneumatic Reservoir Relief Valve The auxiliary pneumatic reservoir relief valve, adjacent to the auxiliary pneumatic reservoir, is connected to the reservoir outlet port. It is a spring-loaded poppet valve that prevents overpressurization of the auxiliary pneumatic reservoir. Valve cracking pressure is 4,500 psi; full flow occurs at 5,100 psi. The valve reseats when the auxiliary pneumatic pressure drops to 4,100 psi. Auxiliary Pressure Reducer The auxiliary pressure reducer, located downstream of the auxiliary pneumatic reservoir, reduces pneumatic pressure (to 325 psi) applied to the auxiliary unlock pneumatic release valve. Auxiliary Unlock Pneumatic Release Valve The auxiliary unlock pneumatic release valve, aft of the canopy, is a lever-operated shutoff valve that is connected by a cable-and-pulley assembly to the canopy control handle in the pilot and NFO stations. It is a two-position valve operated by an eccentric cam mechanism and detented to main- tain the open position. An internal vent releases pneumatic pressure when the auxiliary mode is not selected. When the auxiliary mode is selected to unlock the canopy, the vent port is blocked to per- mit pneumatic pressure application to the un- lock shuttle valve. After each auxiliary mode operation, the cam must be reset manually to return the system to normal. Unlock Shuttle Valve The unlock shuttle valve, aft of the canopy, is a three-port, pressure-operated valve. An in- ternal spool is shuttled by pneumatic pressure at either end of the valve housing to block one of the two end inlet ports. When the canopy control handle is moved to the OPEN position, pneumatic pressure flows from the canopy pneumatic control module, through the shuttle valve and the unlock actuator restrictor, to the unlock side of the canopy-lock pneumatic actuator. In the auxiliary mode (AUX OPEN), auxiliary pneumatic pressure shuttles the valve spool in the opposite direction to route auxiliary pneumatic flow from the auxiliary unlock release valve to the unlock end of the canopy-lock pneumatic actuator. EMERGENCY CANOPY JETTISON SYSTEM The emergency canopy jettison system (fig. 2-3) jettisons the canopy clear of the cockpit 2-5