ATHENS, Aug. 22 (Xinhuanet) -- The possible cause of the Cypriot airliner Aug. 14 crash, which killed all 121 people on board, has been identified as loss of cabin pressure, according to a preliminary investigation report released Monday.

    Chief investigator and head of the Greek Airline Safety Committee Akrivos Tsolakis said information gathered from autopsies and data from black boxes show the doomed plane crashed after it run out of fuel following a loss of cabin pressure.

    After Greek air traffic control unsuccessfully tried to communicate with the flight, the Greek Air Force scrambled two F-16 fighter jets to intercept the plane before it finally crashed.

    The fighter pilots said they witnessed the co-pilot slumped unconscious in his seat and noted that the pilot was not in his seat. Instead, they saw a man wearing an oxygen mask sitting in the pilot's seat.

    In his progress report to Transport and Communications MinisterMichalis Liapis, Tsolakis explained that a problem with the cabin's pressure system would affect people's well-being, which would explain why the co-pilot seemed to be unconscious in the cockpit.

    According to the report, the man seen by the fighter pilots wasidentified as flight attendant Andreas Prodromou, who was trying to send last-minute distress calls and regain control of the aircraft. His efforts failed, however, because the plane's communication system was set to the wrong frequency.

    Tsolakis emphasized that other factors also must be thoroughly examined before the investigation comes to a conclusion, including toxicological reports by medical examiners, examination of the plane manufacturer's findings, testimony of all involved parties, maintenance records and data from the two black boxes.

    Helios Airways flight ZU 522, flying from Larnaca, Cyprus to Athens, crashed into a mountainous region near Athens in Greece's worst air disaster on Aug 14.

    A complete report of the air crash investigation findings is due in about six months, and the contents will be made public, said government spokesman Theodoros Roussopoulos. Enditem