The internal initiator is used to actuate the canopy and hatch system without activating the ejection seat system. Three internal initiators are located in the S-3A aircraft crew compartment. One initiator is located in the overhead between the pilot and copilot. The other two are located at the TACCO and SENSO positions on the out-board side of each instrument panel (fig. 2-15). The initiator is a mechanically actuated sealed-in device containing a squeeze-to-pull type of han-dle (fig. 2-1 5), a mechanical firing mechanism, and a transfer booster assembly. The mechanical firing mechanism and transfer booster assembly are identical to those used in the external system.

Figure 2-15.- Internal canopy and hatch jettison initiator.

The firing mechanism is secured in the safe position by a safety pin that passes through the handle. The safety pin prevents the handle from being squeezed and pulled. When the initiator handle is squeezed and pulled for a distance of 0.75 inch, the firing pin separates from the sear pin. From this point, the sequence is identical to the external canopy and hatch jettison sequence.