What happened
On June 20, 2015, an Aerospatiale SNI EX NORD 1002, registration LN-WNM, was performing a private flight at Elverum Airport Starmoen. The pilot, who was participating in a local aviation event and had recently completed flight instruction in a different aircraft type, was conducting a short proficiency flight accompanied by an experienced pilot and one passenger.
During the landing sequence, the pilot executed a standard three-point touchdown on the 8-meter wide asphalt runway. As the aircraft decelerated, it drifted toward the left edge of the paved surface. The pilot attempted to correct the drift by applying right rudder; however, this maneuver caused the tail to swing sharply to the left. In an attempt to regain control, the pilot applied full left rudder and left braking, but the aircraft continued to rotate. As the main wheels re-entered the asphalt, the aircraft veered violently to the right. The force of the maneuver caused the main landing gear to collapse, forcing the aircraft onto its belly and causing the propeller to strike the runway.
There were no injuries among the three occupants, though the aircraft sustained significant damage to the propeller, the main landing gear, and the landing gear attachment structure.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the flight conditions, the pilot's recent experience, and the physical mechanics of the landing. The investigation noted that while the weather was clear with excellent visibility, the pilot had very limited recent experience on this specific aircraft type, having flown it for only three hours in total.
Findings
- The accident was a classic ground loop, a phenomenon common in tailwheel aircraft where the center of gravity is located behind the main wheels, creating inherent instability during ground operations.
- The pilot's attempt to correct the leftward drift with aggressive right rudder input caused an overcorrection, leading to the uncontrolled rotation.
- The narrowness of the asphalt runway at Starmoen left little margin for error, and the transition between the asphalt and the adjacent grass surface contributed to the instability.
- The investigation concluded that the ground loop might have been avoided if the pilot had allowed the aircraft to continue onto the adjacent grass surface or had opted to land on the grass runway instead.