What condition must an Automated External Defibrillator (AED) meet during preflight?

The condition that an Automated External Defibrillator (AED) must meet during preflight is that the green light must be blinking. This blinking green light indicates that the AED is in a state of readiness and that it is functioning properly, ensuring that it can be used effectively in the event of a cardiac emergency. It's a visual confirmation that the device has passed its self-check and is equipped with sufficient battery power to operate.

During preflight checks, ensuring that the AED is operational is critical for passenger safety, as timely access to a defibrillator can greatly increase the chances of survival in cases of sudden cardiac arrest. Other options, such as breaking the seal or opening compartments, do not contribute to verifying the AED's operational status or readiness for use in an emergency.