What is the first step in the preflight check for the Lifepack 500 AED?

The first step in the preflight check for the Lifepack 500 AED is to check that the LCD reads OK. This step is crucial because the readiness of the device is indicated through the display. An LCD that shows an "OK" message ensures that the AED is operational and that the self-checks have been passed, which is critical for the device's effectiveness in an emergency.

While ensuring the device is powered on, verifying battery status, and confirming that it is in a visible location are important tasks in the overall assessment of the AED, checking the LCD is the initial action that confirms the device's readiness for use. It helps establish a baseline for subsequent checks and assures the flight crew that the AED is indeed prepared for potential life-saving use.