What happened
On July 4, 2011, at approximately 15:00 local time, a Morane-Saulnier MS880 aircraft, registration F-GBCZ, was performing a glider tow takeoff at the Dijon Darois aerodrome. During the takeoff roll, the glider positioned itself approximately 3 meters above the tow plane. As the aircraft reached a speed of roughly 85 km/h, it experienced a sudden, abrupt rotation, pitching up to an angle exceeding 45 degrees.
During this high-pitch maneuver, the towline was released, freeing the glider. The glider pilot successfully landed on the remaining runway, though the towline remained attached to the aircraft. The tow plane continued its steep ascent for several seconds before stalling to the right at an altitude of only a few dozen meters. The aircraft entered a 360-degree turn before impacting the ground. The accident resulted in one fatality and the destruction of the aircraft.
The investigation
Investigators examined the wreckage and found no mechanical malfunctions contributing to the accident. The elevator trim was found in the neutral position, and the aircraft's weight and balance were within manufacturer limits. Witnesses confirmed the engine was at full power until the moment of the stall.
An investigation into hangar practices revealed that it is customary at the club to secure the control stick in a full-aft position using a waist belt to prevent the elevator from striking nearby gliders. The chief pilot had noted the previous day that the aircraft's elevator was indeed positioned in the full-aft position. While the belt was found detached, its exact position during the takeoff could not be determined.
Findings
Analysis of the flight dynamics showed that when a glider flies slightly above a tow plane, it exerts a nose-down pitching moment on the aircraft. To compensate, the pilot must apply back-pressure. Upon release of the glider, the sudden disappearance of this nose-down force creates a significant nose-up tendency.
The investigation concluded that the excessive pitch-up position of the elevator during takeoff caused the aircraft to stall. It is highly probable that the control column had been blocked in the full-aft position by a safety belt, making it impossible for the pilot to counter the pitch-up tendency following the glider release.