What happens if cockpit pressure altitude rises above 19,000 feet?

When cockpit pressure altitude rises above 19,000 feet, the system is designed to alert the crew that cabin pressurization levels are not maintaining an adequate pressure. This is indicated by the illumination of the amber CKPT ALT annunciator. The amber color signifies a caution status, prompting the flight crew to take appropriate measures to assess and address the situation as necessary.

This alert is critical because it serves as an early warning system, ensuring pilots remain aware of cabin pressurization issues that could impact safety and comfort. While other responses like the illumination of a red CKPT PX annunciator would indicate a more urgent situation related to cabin pressure, and a warning horn or activation of the oxygen system might occur under more severe conditions, the amber CKPT ALT alert is the first step in notifying pilots that they need to pay attention to the pressure status in the cockpit as it approaches a high altitude threshold.