Summary
On Thursday, February 10, 2011, at 17:30 local time, a Robin DR 400-180 registration F-GXGA operated by a local flying club departed from Toulouse-Lasbordes aerodrome (31) runway 16 for a flight to Alès (30). The aircraft was carrying the pilot and two passengers. Shortly after rotation, at an estimated height of between five and ten meters as observed by two air traffic controllers in the tower, the aircraft banked sharply to the right. The pilot reported that the control stick was jammed and he could not counter the roll. The stall warning did not activate. An emergency landing was initiated on the prepared strip approximately 400 meters from the threshold of runway 16, on a magnetic heading of 210°. The aircraft continued rolling for 150 meters before crossing the Hers River, which borders the aerodrome below, and came to a stop on the opposite bank partially submerged. Two passengers sustained injuries; the aircraft was destroyed.
Circumstances
The pilot had increased the rotation speed by five knots to 60 knots due to an estimated takeoff mass of 970 kg. Pre-takeoff control checks revealed no anomalies. The aircraft was slightly forward of the center of gravity at takeoff. The pilot stated that immediately after liftoff, the aircraft banked steeply to the right and the stick was blocked. He decided to land on the strip and applied brakes, but could not prevent the aircraft from leaving the aerodrome boundaries. The flight was planned to drop off the front-seat passenger in Alès, with a return to Toulouse the following day. The pilot, who was also an instructor, invited one of his students to join for an instructional flight on the return leg. The pilot estimated the onset of night at 18:45 in Alès, but the aeronautical night for that location on the day of the accident was 18:35. He had reviewed the weather forecast (TAF for Nîmes-Garons) and called a contact on site who reassured him about conditions. Diversion to Valence was planned if needed. The pilot noted that any delay in departure would further compromise arrival before night. During boarding, the rear right passenger asked the front right passenger to move her seat forward; she only partially succeeded. The engine start occurred at 17:15. The previous flight, which landed at 16:50, revealed no anomalies with F-GXGA.
Investigation
Controllers in the tower observed the aircraft's belly after rotation, confirming a steep right bank and a high pitch attitude. Performance calculations and altitude winds suggested a flight duration of 1 hour 15 minutes, leading to an earliest landing time of 18:45, after the start of aeronautical night. Given the restrictions on the VAC chart and weather conditions, the destination aerodrome was not accessible for VFR night operations. Examination of the wreckage found no mechanical failure that could explain the roll control jam. The flaps were set to the first notch, the elevator trim in the takeoff range. No visible marks were found on the control sticks on either the pilot or passenger side. The baggage and personal effects present in the cabin at the time of the accident were removed before investigators arrived, preventing determination of their position or influence on control stick freedom.
Conclusions
The accident resulted from a loss of roll control during takeoff. The origin of the control stick jam experienced by the pilot immediately after rotation could not be determined. However, no evidence of mechanical dysfunction in the control linkages was found. It could not be ruled out that the front passenger's seat slid backward during rotation and that she reflexively grabbed the stick, or that an object obstructed the roll control. The time pressure created by the desire to arrive before aeronautical night likely led to a rushed boarding process.