To activate the E-2 aircraft CF3Br fire extinguishing system shown in figure 1-23, pull the fluid cutoff handle for the affected engine. This action turns off combustible fluids, feathers the propeller, and shuts down the engine. Pulling this handle exposes the fire extinguisher switch. Pressing the fire extinguisher switch completes the electrical circuit necessary to detonate the explosive change in the bonnet assembly of the container (fig. 1-24). This explosion ruptures the frangible disc in the container and allows CF3Br to flow into the

Figure 1-23.- Typical CF3Br fire extinguishing system.

engine nacelle. A screen in the bonnet (fig. 1-24) prevents the segments of the shattered disc from being expelled into the distributing assembly. The CF3Br agent discharges from the distributing assembly as a spray, which (in the presence of heat) turns into a dense gas. This gas reduces the oxygen supply content of the area and effectively smothers the fire.