What do the L/R ENG FIRE PUSH switch light do?

• A. Closes the affected: Fuel SOV, Bleed SOV, Hydraulic SOV, and Trips the affected Engine Generator; Arms both squib bottles
• B. Opens the SOVs
• C. Activates fire extinguishing in the engine compartment only
• D. Displays a separate warning light on the cockpit panel

Answer: (A)

The L/R engine fire push switch light triggers the engine fire suppression and isolation sequence. When the switch is pressed on the affected engine side, it closes the fuel shutoff valve, the bleed air valve, and the hydraulic shutoff valve, effectively isolating the engine from fuel, bleed air, and hydraulics to starve any fire. It also trips the engine’s generator to disconnect electrical power from that engine. In addition, both extinguishing squib bottles are armed so that, if a fire is detected or the system is commanded to discharge, the extinguishing agent can be released into the engine compartment. The light on the switch is simply indicating that this suppression sequence has been activated; it isn’t by itself performing any of these isolations or extinguishing actions.