FAA Powerplant Written Practice Test

How is the engine fire extinguishing agent discharged on a Boeing 777?

1. By using a manual lever

2. By pulling the fire handle and rotating it to the mechanic stop

3. Automatically upon fire detection

4. By pressing a button on the control panel

The correct answer is: By pulling the fire handle and rotating it to the mechanic stop

The discharge of the engine fire extinguishing agent on a Boeing 777 involves a specific procedure that ensures safety and efficacy during an emergency. The correct process includes pulling the fire handle, which activates the system, and then rotating it to the mechanic stop. This action not only triggers the release of the extinguishing agent but also ensures that the system is locked in position, preventing accidental discharge. The design of this method reflects a focus on both pilot control and safety, as it requires deliberate actions to release the extinguishing agent. This is crucial in high-stakes situations where precise control is necessary to manage an engine fire. The mechanism is engineered to prevent unintentional use and ensure that the crew follows a standard procedure that has been established for handling such emergencies. This method differs from automatic systems that would discharge without pilot intervention or from control panels that might not provide the same level of assurance and control during a fire incident. By requiring a deliberate action, the system minimizes the risk of premature discharge that could occur under less controlled scenarios.