The deadliest aviation accident in Greek history, killing all 121 aboard due to crew failure to detect an improperly set cabin pressurization system.
Key Facts
- Date of crash
- 14 August 2005
- Total fatalities
- 121 people
- Aircraft type
- Boeing 737-300
- Route
- Larnaca to Prague via Athens
- Cause
- Pressurization set to manual; crew hypoxia
- Operator shut down
- Helios Airways, 2006
By the Numbers
Location
Cause → Event → Consequence
Before the flight, a ground engineer set the cabin pressurization system to 'manual' during testing and most likely forgot to restore it to 'auto.' The flight crew failed to catch this misconfiguration during pre-flight checks, allowing the aircraft to depart with the pressurization system in an unsafe state.
Shortly after takeoff from Larnaca on 14 August 2005, the Boeing 737-300 gradually depressurized as it climbed. All 121 passengers and crew suffered critical hypoxia, rendering the pilots incapacitated. Nicosia ATC lost contact with the flight, and the aircraft eventually crashed near Grammatiko, Greece, killing everyone on board.
Greece's AAIASB investigation concluded the accident resulted from crew and ground-crew negligence. Lawsuits were filed against both Helios Airways and Boeing. The Government of Cyprus shut down Helios Airways the following year. The crash remains the deadliest aviation accident in Greek history and prompted scrutiny of pre-flight pressurization check procedures.