What happened
On 25 May 2022, a Diamond DA 42 NG, registered as N591ER, was performing a local test flight at London Airport, Ontario. The flight was intended to verify the results of a major overhaul recently completed at the Diamond Aircraft Industries Inc. facilities located at the airport.
As the aircraft departed Runway 09 and became airborne, it experienced an abrupt yaw to the left. The pilot struggled to maintain directional control despite attempts to correct the movement. Seeking an emergency landing, the pilot targeted Runway 27, but persistent control difficulties forced a shift in plans toward Taxiway A. The aircraft ultimately impacted the grass area situated between the runway and the taxiway.
Upon the hard impact with the ground, the mass balance weight for the left-wing aileron and the rudder detached from the aircraft. The landing gear subsequently collapsed, causing the aircraft to slide approximately 265 feet before coming to a halt. There were no injuries to the pilot, though the aircraft sustained substantial damage.
The investigation
Investigators examined the aircraft to determine the source of the directional instability. During the post-incident inspection, it was established that the rudder was moving in the opposite direction of the pilot's inputs.