What happens when an engine fire switch is pulled?

• A. The hydraulic pump LOW PRESSURE light is deactivated
• B. The standby hydraulic system is engaged
• C. The engine stops immediately
• D. The hydraulic fluid is dumped

Answer: (A)

When the engine fire switch is pulled, one of the key actions typically taken is that the hydraulic fluid is directed appropriately to prevent the risk of fire spreading, which could include shutting down systems that are no longer necessary. The correct understanding is that the activation of the fire switch is usually associated with the deactivation of certain system indicators, such as the hydraulic pump LOW PRESSURE light. This action ensures that the hydraulic system is safeguarded during an emergency, particularly because this system operates under high pressures and any leakage could exacerbate a fire situation.

The other options do not accurately reflect the functions of the engine fire switch. The standby hydraulic system usually operates independently and may be engaged under different circumstances, not directly related to the engine fire switch. Stopping the engine is a critical step but may not occur instantaneously with the switch pull; there are additional steps involved in that process. Dumping hydraulic fluid would typically be a last resort to manage fire risk, and while certain valves might be engaged, it's more about isolating the system than simply dumping fluid.