What is the first step in the exit door arming procedure?

The first step in the exit door arming procedure involves securing the strap. This is crucial because the strap helps to establish an appropriate connection between the door and the aircraft's emergency systems. When arming the exit door, ensuring the strap is correctly positioned is vital for the subsequent steps to function correctly.

This initial action is about securing the door in its armed state and making sure that it will deploy correctly in an emergency situation. Properly arming the door sets the stage for safe evacuation, as it controls how the exit will open and ensures that the emergency slide is ready for deployment when activated. Understanding this sequence is important for ensuring passenger safety during an emergency evacuation.