What is one of the safety characteristics of the CPCS regarding cabin altitude?

The correct answer highlights a critical safety feature of the Cabin Pressure Control System (CPCS) in aircraft operations. The CPCS is designed to maintain a safe environment for passengers and crew by controlling cabin altitude during flight. When the cabin altitude reaches 14,500 feet, the outflow valve is automatically closed, which prevents further increases in cabin altitude and helps ensure that the pressure remains at a safe level.

This function is particularly important because it protects against hypoxia, a condition that can occur when there is insufficient oxygen available at high altitudes. By closing the outflow valve at this point, the CPCS takes corrective action to maintain a cabin altitude below the threshold where oxygen becomes a concern for occupants. This feature is essential for safety in operations that typically ascend to high altitudes, as it directly mitigates the risks associated with cabin decompression and altitude-related health issues.

Understanding how and when the CPCS operates is vital for ensuring safety and compliance with aviation regulations during flight operations.