The emergency canopy jettison system (fig. 2-3) jettisons the canopy clear of the cockpit

Figure 2-3. Canopy emergency jettison system

during emergency conditions that require emergency ground egress, seat ejection, or ditching. The canopy must be clear of the cockpit before seat ejection. Through the use of pyrotechnics, the canopy is automatically un-locked and jettisoned when seat ejection is initiated. The canopy may be jettisoned without initiating seat ejection by pulling a canopy emergency jettison initiator handle (fig. 2-4), located inside the aircraft or externally (fig. 2-5) on either side of the aircraft. System Operation Pulling the pilot or NFO face curtain or secondary firing control handle initiates seat ejection (fig. 2-3). A system initiator is fired by sear removal. This sends an explosive signal through shielded mild detonating cord (SMDC) lines to the safe-and-arm firing pins, canopy-separation charge expanding SMDC, and canopy gas generator. Expanding SMDC lines, routed through the latch hooks, break the canopy latch frangible bolts and allow the hooks to rotate upward, releasing the canopy. The canopy gas generator produces high-pressure gas that forces the canopy hydraulic actuator shaft upward, ballistically jettisoning the canopy. As the canopy leaves the aircraft, the

Figure 2-5.- Canopy external jettison initiator handle. lanyard for the backup initiator becomes taut and actuates linkage to remove the backup initiator sear. This fires the initiator to send an explosive signal through a 1.1-second time delay. This signal positions an explosive charge within

Figure 2-4.- Canopy emergency jettison initiator handles.

the safe-and-arm seat ejection module for use if the lanyard-operated firing mechanism of the module fails. As previously mentioned, during emergency ground egress, seat ejection, or ditching condi-tions, the canopy may be jettisoned by pulling either an internal or external canopy emergency jettison initiator handle. During emergency ground egress, without seat ejection, the explosive signal provided by the canopy jettison initiator is blocked from entering the SMDC lines of the seat ejection system by the one-way explosive transfers. Inert connectors joining the SMDC lines transfer the explosive stimuli through bulkheads, straight runs, tee connections, and 90-degree bends. Explosive manifolds, within SMDC line runs, allow output SMDC lines to be initiated from one SMDC input. This assures system redundancy by providing dual-line initiation for the canopy-separation charge.