What emergency situation necessitates extensive knowledge of the Cabin Atmosphere Control System by crew members?

Extensive knowledge of the Cabin Atmosphere Control System is crucial for crew members during an emergency descent caused by cabin depressurization. This situation requires immediate action to ensure the safety and well-being of passengers and crew. In the event of depressurization, the cabin altitude rapidly increases, which can lead to a decrease in oxygen levels. Crew members must be familiar with emergency procedures, such as deploying oxygen masks and executing a rapid descent to lower altitudes where breathable air is available. This understanding is essential to effectively manage the emergency and mitigate the risks associated with a sudden loss of cabin pressure, ensuring that all safety protocols are followed in a calm and efficient manner.