Helios Airways Flight 522Sunday August 14, 2005
While flying at FL340 towards Athens the crew reported problems with their air conditioning system. As the airliner entered Greek airspace ATC lost contact with the plane. Two Greek F-16 fighters were dispatched to intercept the plane. The F-16 pilots reported that one pilot was not in the cockpit and the other was slumped over the controls. They also said oxygen masks had deployed in the cabin. The plane continued on its programmed route to a holding pattern off the coast of Greece and flew in circles for two hours. Meanwhile, at least two flight attendants had stayed awake using portable oxygen bottles but they couldn't get through the locked, terrorist-proof cockpit door. It was only when one engine failed from fuel starvation that the computer-controlled systems aboard the plane unlocked the door. The plane continued on track until it crashed into mountainous terrain about 25 miles north of Athens. CVR tapes showed that a student pilot/flight attendant, Andreas Prodromou, was at the controls of the aircraft and tried to send a Mayday message twice but the radio was set to the wrong frequency. The cabin pressure control was left in the manual, instead of auto position by maintenance workers. The error was not picked up by the two pilots during three subsequent check lists. They failed to respond to warnings as oxygen masks fell in the passenger cabin which eventually led to the two pilots losing consciousness and the plane crashing.