What is the first step in the door unsafe procedure?

The first step in the door unsafe procedure is to alert the flight deck. This is crucial because the flight deck needs to be informed of any potential safety issues that could compromise the safety of the aircraft and its occupants. By promptly informing the pilots, they can take necessary actions, such as preparing for an emergency landing or monitoring the situation closely. Communication between crew members ensures everyone is aware of the status and can coordinate effectively during a safety incident.

While other steps in the procedure, such as checking the handle position, evacuating the aircraft, or shutting down the engines, are important, they follow this initial alert to the flight deck. This step is fundamental because it initiates the response protocol and situates the pilots to handle the situation based on the information provided.