What happened
On October 1, 2013, an Airbus A320-214, registration HB-IOR, operated by Belair Airlines, experienced a serious incident during takeoff at Porto Airport, Portugal. While preparing for flight AB778 and following a flight from Palma de Mallorca, the crew initially calculated engine thrust requirements based on a full runway length of 3480 meters to minimize engine wear. However, the crew later decided to perform an intersection takeoff from taxiway Foxtrot to save time, which reduced the available runway length to only 1900 meters.
Crucially, the engine thrust settings were not updated in the flight management system to reflect this shorter distance. During the takeoff roll, both pilots realized the remaining runway was unexpectedly short. The aircraft eventually rotated and lifted off only 350 meters before the end of the runway, passing over the threshold at an altitude of approximately 104 feet. No injuries or damage to the aircraft occurred, and the flight proceeded to Palma de Mallorca as planned.
The investigation
An investigation by the Swiss Transportation Safety Investigation Board (SUST) examined the cockpit preparations and the crew's performance. The inquiry focused on the discrepancy between the calculated takeoff data and the actual runway distance used. Investigators reviewed the pilot's actions, including a period where the captain left the cockpit to attend to a missing passenger, which interrupted the takeoff data entry process. The investigation also looked into the airline's checklist procedures and the way takeoff performance figures were verified by the crew.
Findings
- The primary cause was that the aircraft failed to achieve the required flight performance because the crew performed an intersection takeoff using thrust settings calculated for the full runway length.
- The captain was distracted by external events during the takeoff preparations.
- The takeoff data verification during the 'before start' checklist was incomplete.
- Existing procedures only required certain checks if specific conditions were met, which contributed to the oversight.
- Essential checks were being performed 'silently' without verbal confirmation between the crew members.