What happened
On February 6, 2010, a Hughes 269C helicopter was conducting a private sightseeing flight near the Stralsund airfield in Germany. The pilot had previously been clearing snow from the hangar area and offered a short flight to an assistant.
At approximately 14:15 local time, the pilot began a flight path approaching the airfield from the south. To avoid noise disturbance to the nearby village of Groß Kedingshagen, the pilot chose an approach path over an open field. The intention was to fly at a very low altitude, between 2 and 10 meters, over the snow-covered landscape to land on the cleared area near the hangar. During the descent, the pilot experienced a perceived loss of power, which led to the left skid making initial contact with the ground. While the pilot attempted to regain control and lift the aircraft, the helicopter subsequently struck the ground again, eventually coming to rest on its right side.
The investigation
The BFU investigation focused on the sequence of events and the environmental conditions at the time of the accident. Investigators examined the aircraft, a Hughes 269C, and performed a technical inspection of the Lycoming engine, fuel system, ignition, and oil supply. No evidence of mechanical failure or engine malfunction was found. The investigation also considered the meteorological conditions, noting that while the sky was cloudless, the presence of haze and a continuous layer of snow created specific visual challenges. The investigation also noted that the aircraft was not equipped with a flight data recorder or cockpit voice recorder.
Findings
- The primary cause of the accident was the whiteout phenomenon, which occurred due to the diffuse reflection of sunlight across the vast, snow-covered fields.
- The lack of visual contrast and contours in the landscape, combined with the low flight altitude, led to a loss of altitude and attitude perception by the pilot.
- The pilot's perception of a power loss was likely an error in judgment caused by the inability to accurately sense the aircraft's true height above the ground.
- The aircraft sustained significant damage, including a broken tail boom, destroyed main rotor blades, and a destroyed cockpit frame, resulting in the total loss of the helicopter.
- The pilot sustained serious injuries, while the passenger sustained minor injuries.