Incident Overview
A pilot and an aircraft mechanic departed Grenoble-Alpes-Isère Airport (Saint-Geoirs) to conduct a check flight following maintenance. Once in an open area south of the aerodrome, the pilot began maneuvers specified in the test program.
In-Flight Failure
At the conclusion of a stall maneuver, the pilot found that inputs on the rudder pedals had no effect. However, control of the ailerons and elevators was maintained. The pilot informed the aerodrome controller of the problem and indicated a return to land on paved runway 09.
Unable to determine the exact nature of the damage, the pilot chose to land with the flaps retracted. He managed with difficulty to align the aircraft with runway 09's centerline. On final approach at an altitude of 300 feet, the pilot changed his mind and decided to land on the unpaved right-hand runway 09, which adjoins the paved runway.
Landing and Runway Excursion
On very short final, during the flare while reducing power at a height of approximately 1–2 meters, the aircraft rolled to the right and then to the left, causing the wing tips and propeller to strike the ground. The aircraft exited the unpaved runway to the left and came to rest on the right edge of the paved runway.
Occupant Status and Damage
Both occupants evacuated safely. The aircraft was damaged beyond repair.
Official Findings
The probable cause of the accident was a failure of the rudder control in flight, which led to a significant alteration of the aircraft's yaw controllability. This failure considerably increased the pilot's workload and stress. Under these conditions, it became difficult for the pilot to keep the aircraft aligned with the runway centerline during landing. Monitoring the alignment was done to the detriment of speed. It is very likely that the oscillations during the final step resulted from a stall of the aircraft at low speed.