Accident Sequence
While on short final approach for runway 28, the pilot maintained approximately 121 knots indicated airspeed (KIAS) with flaps selected to 30 degrees. Differential engine power was used to stay on the extended centerline until crossing the runway threshold. After crossing the threshold, the pilot began a landing flare, and the airspeed slowed toward red line (92 KIAS). Shortly before touchdown, the airplane "abruptly pitched up and was pushed over to the left," and flight control inputs were "only marginally effective" in keeping the wings level. The airplane drifted off the left side of the runway and began a "violent shuddering." According to the pilot, flight control inputs "produced no change in aircraft heading, or altitude." The pilot advanced the engine throttles for a go-around as the left wing impacted the terrain. The airplane cartwheeled and subsequently caught fire.
Weather and Ice Conditions
The pilot reported that during cruise descent, about 1/2 to 3/4 inch of rime ice accumulated between 8,000 and 6,000 feet. During the approach, most ice had dissipated from the leading edge of both wings, though trace ice remained on the aft portion of the wing deice boots. The pilot added 20 knots to the approach speed due to gusting winds from the north-northwest and anticipated turbulence from surrounding topography and buildings north of the airport. The reported surface wind was about 4 knots from the north-northwest.
Pilot Actions and Control Issues
The pilot used differential engine power to maintain runway alignment during final approach. After crossing the threshold, as the flare began, the airplane experienced an abrupt pitch-up and left roll. Control inputs were only marginally effective for keeping the wings level, and the aircraft drifted left. During the shuddering, control inputs produced no response in heading or altitude. The pilot initiated a go-around, but the left wing struck the ground.
Postaccident Examination
No pre-impact anomalies were noted with the airplane's flight control systems or deice control valves. No ice shapes were found on the ground leading to the main wreckage.