What is the first step to take in the event of a fire in the AMAD bay?

Opening door 54L/R is the first step to take in the event of a fire in the AMAD bay because it allows for the immediate assessment and access to the area affected by the fire. This procedure is part of the safety protocols designed to ventilate the bay and help mitigate smoke and heat buildup, providing better visibility and access for firefighting efforts. Safety regulations emphasize the importance of quickly assessing the situation and ensuring that firefighters can respond effectively.

The other options, while potentially relevant in the overall fire response procedures, are not the initial actions to take. Turning off all engines could be a necessary step, but it might not be the first thing to do as it may not address the immediate concern of the fire. Activating the automatic fire extinguishing system is crucial, but it usually follows the initial assessment and accessing the area. Injecting water into the AMAD bay could cause further complications, like damaging equipment or creating a hazardous situation, which makes opening the doors the safest and most logical first step.