What happened
Recent safety investigations have highlighted a persistent and complex challenge within the aviation industry: the risk of aircraft departing with incorrect takeoff performance data. Such errors often stem from operational pressures, particularly when last-minute changes occur while an aircraft is taxiing. These discrepancies can lead to highly hazardous situations, including the potential for loss of aircraft or loss of life.
The investigation
The Dutch Safety Board examined the systemic issues surrounding takeoff data accuracy. The investigation found that while various technical and procedural improvements have been implemented globally, a comprehensive, universal solution to prevent data input errors has not yet been fully operationalized across the global transport fleet. The investigation also noted that flight crews often maintain a derated takeoff setting and may fail to select full thrust if they suspect the takeoff roll is not progressing as expected.
Findings
The primary cause of takeoff data errors is the pressure to maintain schedules during last-minute changes while taxiing. The investigation established that the lack of a dedicated stationary moment to recalculate and verify data increases the risk of error. To mitigate this, the Board emphasizes that the aircraft should be stopped to allow the crew sufficient time to independently verify and enter updated performance parameters.
Safety action
To address these risks, the Dutch Safety Board has issued specific recommendations to regulatory and industry bodies:
- To EASA: It is recommended that the agency advise operators and flight crews to utilize a stationary moment for calculating and entering takeoff data following any last-minute changes. This practice should be integrated into safety guidance and information bulletins.
- To KLM Royal Dutch Airlines: The airline is advised to implement measures ensuring that all takeoff performance data changes are processed only while the aircraft is stationary. Furthermore, the airline should develop procedures for crews to prepare alternative plans in advance and encourage the use of full thrust during unexpected changes. Training programs should also be updated to ensure crews are prepared to take decisive action if the takeoff roll deviates from expected performance.