What happened
On 27 October 2008, a Boeing B747-228F operated by Cargo B Airlines was performing a scheduled cargo flight from Brussels to Brazil. During the takeoff roll at Brussels Airport (EBBR), the aircraft experienced an abnormal rotation. The pilot flying noted sluggish controls and a lack of climbing performance. As the aircraft rotated, the tail section made contact with the runway, resulting in a tail strike accompanied by visible sparks, flames, and smoke.
Ground observers and air traffic controllers witnessed parts of the aircraft's underside, including the APU access door, detach from the fuselage. Following the incident, the crew increased engine thrust to successfully become airborne. Due to the structural damage and the risk of fire, the crew performed a fuel dump before returning to Brussels, landing safely approximately 80 minutes later.
The investigation
The AAIU(Be) investigation focused on the takeoff performance parameters and the cockpit environment leading up to the event. Investigators examined the takeoff performance card, the flight management system (FMS) inputs, and the software used for weight calculations. The inquiry also reviewed the crew's experience levels and the sequence of events during the pre-flight preparations.
Investigators found that the takeoff performance computation was based on incorrect data. Specifically, the zero fuel weight (ZFW) was used in the software instead of the actual takeoff weight (TOW). This error resulted in takeoff speeds and thrust settings that were too low for the aircraft's actual mass. Furthermore, the investigation looked into the cockpit atmosphere, noting several distractions, including maintenance interventions and logistical issues regarding animals being transported on the flight.
Findings
- The takeoff performance calculation was fundamentally flawed because the zero fuel weight was entered into the software in place of the takeoff weight.
- The crew failed to follow the operator's standard operating procedures (SOP) regarding the independent verification of takeoff performance data.
- The crew's ability to detect the error was compromised by a lack of distraction management and the presence of several interruptions during the pre-flight checklist.
- The pairing of crew members with relatively low experience on the B747 type contributed to the failure to recognize that the takeoff speeds and engine power settings were inappropriate for the aircraft's weight.