What are critical care actions if an APU fire is suspected?

The correct response emphasizes the importance of immediate action when a fire is suspected in the Auxiliary Power Unit (APU). Activating the fire suppression system and shutting down the APU are critical steps to ensure both aircraft safety and crew protection.

When a fire is suspected, using the fire suppression system helps to actively combat the potential flames, minimizing the risk of a larger fire and protecting the aircraft's integrity. Shutting down the APU halts any fuel or electrical flow, which can further prevent the fire from spreading or escalating. These actions are in line with established safety protocols and best practices for dealing with APU fires, reflecting a proactive approach to emergency management.

Effective emergency response not only mitigates immediate risks but also helps in maintaining operational readiness and safety for crew members and personnel on board. In contrast, other choices might lead to delayed responses or increased risks, highlighting the critical nature of the appropriate actions in the event of a fire.