Which system is responsible for ensuring the cabin doesn’t exceed the structural pressure limits?

The automatic controller mode is responsible for managing the cabin pressure to ensure it remains within structural limits. This system automatically adjusts the outflow valve and other components to maintain safe cabin pressurization according to the aircraft's altitude and operational needs.

Maintaining cabin pressure is critical for passenger and crew safety as well as structural integrity. The automatic controller continuously monitors cabin altitude and adjusts airflow to prevent over-pressurization, which can lead to structural damage. This proactive management is essential during ascent and descent phases of flight.

While the over pressure safety valve does help in preventing over-pressurization by venting excess pressure when necessary, it is more of a failsafe rather than a primary control system. The negative pressure relief valve addresses conditions of negative pressure, ensuring the cabin does not become pressurized to the point of structural failure under under-pressure situations. The cabin altitude warning system is designed to alert crew to excessive cabin altitude but does not actively control pressure.