What happened
On 14 August 2005, a Boeing 737-300, registration 5B-DBY, departed from Larnaca, Cyprus, bound for Prague via Athens. During the initial climb, the captain notified the airline's operations center regarding an equipment cooling issue and a take-off configuration warning. While climbing through 18,200 feet, the passenger oxygen masks deployed in the cabin. Following several minutes of communication with the ground, the aircraft ceased all radio contact.
The flight continued on its programmed route, eventually entering a holding pattern near the KEA VOR. At approximately 08:24, two Hellenic Air Force F-16 fighters intercepted the unresponsive aircraft. Upon close inspection, the intercepting pilot observed that the captain's seat was empty and the first officer was slumped over the controls. The pilot also noted dangling oxygen masks and motionless passengers inside the cabin. Later, an individual was seen entering the cockpit and sitting in the captain's seat, but they did not respond to signals from the F-16.
The aircraft's left engine failed at 08:50 due to fuel exhaustion, followed by the failure of the right engine at 09:00 while at 7,100 feet. The aircraft entered a rapid descent and struck hilly terrain near Grammatiko, Greece, at 09:03. The crash resulted in 121 fatalities, involving all 115 passengers and 6 crew members on board.
Findings
Investigations determined that the primary cause was the failure to recognize that the cabin pressurization selector had been left in the manual position during preflight and post-takeoff checklists. This error led to a loss of cabin pressure, causing the hypoxia-induced incapacitation of the flight crew.
Additional contributing factors included:
- Failure to identify and react to various cockpit warnings, such as the cabin altitude warning horn.
- The omission of returning the pressurable mode to auto following recent maintenance.
- Organizational and safety culture deficiencies within the operating airline.
- Inadequate oversight by the relevant regulatory authority.
- A lack of standardized international procedures for cabin crews to manage depressurization events during a climb.