premise: A Helios airliner (Boeing 737, flight HCY 522) with 115 passengers and 6 crew onboard has crashed into a mountain at 09:04 UTC (12:04 p.m. EEST) near Grammatiko, 40 kilometres (25 miles) north of Athens, while approaching the capital's airport. All on board perished. The plane was travelling from Larnaca, in the southeast of Cyprus (Greek:Kypros) and scheduled to arrive in Prague after a stop in Athens. In-flight events Immediately after take-off, the pilots reported a problem with the air conditioning system of the aircraft and requested to stay at a low altitude. A few minutes later, the pilots alerted the station that the problem had been fixed and requested permission to ascend. This information however has been denied by the Director of Helios Airways. As the plane approached Athens, all communication abruptly ceased, and the plane never issued a mayday distress signal. Two Greek F-16 military aircraft were assigned to observe the plane. The pilots of the F-16s noted that one airliner pilot appeared to be unconscious and the other was not in the cockpit.
hypothesis: 26 people died in an airplane crash.