What happened
On 10 October 2006, a Fairchild SA227 AC Metro III, registration EC-JCU, was performing a commercial cargo flight from Coventry to Lasham Airfield. The aircraft was lightly loaded with a center of gravity positioned near the forward limit of its allowable range. During the takeoff roll on Runway 09, the co-pilot, acting as the handling pilot, initiated the rotation sequence following the commander's instructions. However, the aircraft failed to respond as expected to the initial control inputs.
Upon perceiving a potential control malfunction, the commander took control of the aircraft. Realising the end of the paved surface was approaching rapidly, the commander decided to abort the takeoff, applying maximum braking and reverse thrust. Despite these efforts, the aircraft overran the end of the runway, travelling approximately 34 metres beyond the paved surface into an area of grass stubble. There were no injuries to the two crew members on board, though the aircraft sustained tyre damage and required the replacement of all four brakes due to overheating.
The investigation
The AAIB investigation focused on the aircraft's handling characteristics and the reliability of the flight data recorder. Technical examinations of the elevator control system and the pitch trim actuator revealed no mechanical obstructions or malfunctions that would have prevented rotation. The investigation established that for this aircraft type, a significant aft movement of the control column is necessary to achieve rotation when the center of gravity is at the forward limit.
Investigators also identified a defect in the Flight Data Recorder (FDR), which failed to record valid airspeed data during the takeoff roll. Analysis of the FDR showed that the airspeed parameter had been recording inaccurately for several previous flights, jumping from zero to approximately 65 kt during takeoff. While a leak was found in the right pitot system, it was not considered a contributing factor to the overrun.
Findings
- The aircraft was operating with a center of gravity near the forward limit, which necessitates much larger control column movements for rotation than the co-pilot initially applied.
- The co-pilot's relative inexperience with the required handling characteristics for a forward CG configuration contributed to the perceived lack of control response.
- The decision to reject the takeoff was made with very little time remaining before the end of the runway, making a successful stop on the remaining paved surface difficult.
Safety action
- Safety Recommendation 2007-060: It is recommended that the European Aviation Safety Agency require operators to perform annual operational checks and evaluations of FDR recordings to ensure the validity of all recorded parameters and system serviceability.