Which system is NOT a component firefighters must know about in aircraft systems?

Understanding the systems of an aircraft is crucial for firefighters responding to incidents involving aircraft, as different systems pose varying hazards. The correct answer indicates that electrical systems are not required knowledge for firefighters in this context.

While knowledge of a range of systems is vital for effective firefighting and rescue operations, especially in the realms of potential hazards and responses, electrical systems are often managed and understood by specialized personnel in the maintenance sector. Firefighters focus more on systems that present immediate risks during emergencies, such as fuel systems, which can create fire hazards, oxygen systems, essential for understanding potential fire behavior and risks, and landing gear and brake systems, which are critical in assessing rescue operations and the operational state of aircraft during an incident.

Thus, while knowledge of all aircraft systems can enhance overall situational awareness, in the specific context of immediate firefighting protocols, electrical systems are generally secondary to the other more hazardous or relevant systems commonly encountered during such emergencies.