On August 14, 2005, Helios Airways Flight 522, a Boeing 737, took off from Cyprus bound for Prague, with a stop in Athens. Shortly after takeoff, the cabin pressure system malfunctioned, leading to a gradual decrease in oxygen levels. The pilots reported an air conditioning issue, but radio communication soon became chaotic and eventually ceased. The aircraft continued on its programmed flight path over the Mediterranean Sea, flying for nearly three hours on autopilot, while all 121 individuals on board were incapacitated due to hypoxia. Greek military fighter jets intercepted the plane and observed the pilot motionless at his controls, with the co-pilot slumped against the control levers. Despite efforts by a cabin crew member, Andreas Prodromou, to regain control, the plane ultimately crashed into the hills surrounding Grammatiko, Greece, after running out of fuel. Investigations revealed that the cabin pressurization system could have been manually switched during maintenance, and the alarm sounds may have confused the crew during the emergency. This tragic incident remains a stark reminder of how minor technical issues can lead to catastrophic outcomes in aviation.