What is one tool used to communicate during an in-flight emergency?

The intercom system is a critical tool used to communicate during an in-flight emergency because it allows for direct and clear communication between the flight crew and passengers. In situations where rapid dissemination of information is necessary to ensure passenger safety, the intercom system enables the crew to make important announcements, provide instructions, and maintain order.

This system is specifically designed for in-flight use, ensuring that messages can be broadcasted throughout the cabin without interference from external noise or limitations that other tools might face. The intercom is integrated into the aircraft's systems, making it reliable, accessible, and efficient for communicating critical information during emergency situations.

While the passenger announcement system is also a valid communication tool, it typically refers to public announcement capabilities that may be more formal or may not be as immediate as the intercom system during an emergency. Emergency lights serve a different purpose by providing visibility and guidance in the cabin during a crisis, and mobile phones are not generally reliable or permitted for use during flight operations.