What action should be taken when the Door Unlocked CAS message illuminates?

When the Door Unlocked Critical Alert System (CAS) message illuminates, the first action should be to get out the Pilot's Checklist (PCL) or consult the NATOPS (Naval Air Training and Operating Procedures Standardization) manual. This resource provides specific guidance on how to address the situation effectively and safely. The PCL contains procedures that outline steps to verify the status of the door and mitigate any potential risks associated with an unlocked door during flight, which could include cabin pressure or safety issues.

Other options involve immediate actions that may not directly address the indicated warning. Informing air traffic control is important in various emergency situations but is not the first step when addressing a door unlocked alert. Similarly, proceeding to emergency landing procedures might be premature unless the situation escalates and other checks confirm a critical issue. Checking fuel levels is also unrelated to addressing the alert about the door being unlocked and does not contribute to resolving the immediate safety concern presented by the CAS message. Prioritizing the use of the PCL ensures that the crew follows the established protocols for such alerts, maintaining safety throughout the flight.