Firewall

Firewall is a fire-resistant bulkhead separating the engine compartment from the aircraft structure, cabin, or fuel tanks. Made from stainless steel, titanium, or fire-resistant composite materials, the firewall prevents engine fires from spreading to the rest of the aircraft.

In multi-engine aircraft, pulling the engine fire handle closes the firewall shutoff valve, cutting fuel, hydraulic fluid, and bleed air supply to the affected engine, while activating the fire extinguisher bottles.