Helios Airways Flight 522 was a scheduled international passenger flight from Larnaca, Cyprus, to Prague, Czech Republic, with a stopover in Athens, Greece, operated by a Boeing 737-300. Shortly after takeoff on 14 August 2005, Nicosia air traffic control (ATC) lost contact with the pilots operating the flight; it eventually crashed near Grammatiko, Greece. All 121 passengers and crew on board were killed. It is the deadliest aviation accident in Greek history.