The doomed Helios Airways plane twice tried to land at Athens International Airport before running out of fuel and crashing into a mountainside north of Athens on Sunday, according to official documents, prompting questions about a possible delay in response from the Greek Civil Aviation Authority. Investigators are still combing the scene of the crash in Grammatiko, some 40 kilometers north of Athens, for clues as to what caused the accident, in which all 121 passengers and crew members on board were killed. However, aviation documents obtained by SKAI Radio seem to indicate that after entering Greek air space, the plane circled around islands east of Athens, including Kea, but that someone on board attempted to land the plane on two separate occasions. The pilots of the two F-16 Greek air force jets that were dispatched to monitor the situation after radio contact with the aircraft proved impossible, said they saw the co-pilot slumped over the controls of the plane and the captain missing from his seat, but noticed two other figures in the cockpit. One theory is that a stand-in member of the cabin crew, trained pilot Andreas Prodromou, and his air hostess girlfriend Haris Charalambous, tried to wrestle control of the plane and land it in Athens. The fighter jets were sent out after the Greek Civil Aviation Authority classified the plane as «renegade,» meaning there was a possibility it had been hijacked. However, the authority looks set to come in for criticism over a period of apparent inactivity while the plane was in Greek air space. The plane entered Greek air space at around 9.30 a.m. but air-traffic controllers did not make any attempt to contact it until almost 40 minutes later. Sources told Kathimerini that military authorities were first informed of the possibility of a «renegade» aircraft at 10.24 a.m. but 23 minutes later told them that the plane was experiencing a problem which the crew was trying to fix. The F-16s eventually took off a few minutes later. The investigation into the crash has been inconclusive so far, but after a meeting in Athens yesterday Cypriot President Tassos Papadopoulos said that he and Prime Minister Costas Karamanlis had agreed to speed up the probe. Meanwhile, sources told Kathimerini that CIA experts who examined the scene have ruled out the possibility that the plane had been tampered with, including by terrorists. Meanwhile, results of toxicological tests on some of the bodies recovered are expected today and should give a better idea of conditions inside the plane before the crash, especially if those on board had inhaled toxic substances.