Helios Airways Flight 522 was a scheduled passenger flight from Larnaca, Cyprus, to Prague, Czech Republic, with a stopover in Athens, Greece. Shortly after take-off on 14 August 2005, air traffic control (ATC) lost contact with the aircraft operating the flight, named Olympia; it eventually crashed near Grammatiko, Greece, killing all 121 passengers and crew on board. It is the deadliest aviation accident in Greek history. An investigation into the crash by the Air Accident Investigation and Aviation Safety Board (AAIASB) concluded that the crew had neglected to set the pressurization system to automatic during the take-off checks. This caused the plane not to be pressurized during the flight and resulted in nearly everyone on board suffering from hypoxia, thus resulting in a ghost flight. The negligent nature of the accident led to lawsuits being filed against Helios Airways and Boeing, with the former also being shut down by the government of Cyprus the following year. Background The aircraft involved in this accident, initially registered as D-ADBQ, was a Boeing 737-300, first flown on 29 December 1997, and was operated by DBA from 1998 unil 2004. It was then leased by Helios Airways on 16 April 2004, and was re-registered 5B-DBY with the nickname Olympia. Besides the downed aircraft, the Helios fleet also included two leased Boeing 737-800s and an Airbus A319-100, which were delivered on 14 May 2005. The plane had arrived at Larnaca International Airport at 01:25 local time on the day of the accident. It was scheduled to leave Larnaca at 09:00 and fly to Prague Ruzyně International Airport, with a stop off at Athens International Airport, where it was due to arrive at 10:45. The captain of the flight was Hans-Jürgen Merten, a 58-year-old German contract pilot hired by Helios for holiday flights, who had been flying for 35 years (previously for Interflug from 1970 to 1991), and had accrued a total of 16,900 flight hours (including 5,500 hours on the Boeing 737). The first officer was Pampos Charalambous, a 51-year-old Cypriot pilot who had flown exclusively for Helios for the past five years, accruing 7,549 flight hours throughout his career (3,991 of them on the Boeing 737). Louisa Vouteri, a 32-year-old Greek national living in Cyprus, had replaced a sick colleague as the chief flight attendant. Flight and crash When the aircraft arrived at Larnaca from London earlier that morning, the previous flight crew had