What is the first step in the emergency procedures for an APU Fire?

In the event of an APU fire, the primary focus is on communication and ensuring the safety of all personnel involved. Signaling the pilot with large lazy 8's is critical because it serves to alert them of the emergency situation, enabling them to take immediate action to mitigate the threat. This method of signaling is a well-established protocol that helps in maintaining clear communication during emergencies, ensuring that the pilot is aware of the situation before proceeding with any further emergency procedures. This action also reinforces the role of teamwork in emergency scenarios, where the Plane Captain assists the pilot in managing the incident effectively.

The steps such as shutting down the APU or opening specific doors are important but come after ensuring that the pilot has been notified about the situation. Communicating effectively in an emergency can be crucial for the safety of personnel and the proper management of the aircraft’s systems.