What happened
The incident occurred while the pilot was conducting a Global Positioning System (GPS) approach toward runway 28. During the descent, ice began to accumulate on the airframe, degrading aerodynamic performance. As the aircraft broke through the cloud layer at an altitude of 1,600 feet above ground level, the pilot encountered significant challenges in visually acquiring the runway due to extensive snow cover on the terrain.
Upon reaching short final approach, the pilot reported maintaining an airspeed of approximately 100 knots, which corresponded to about 65 percent power. As the aircraft crossed the runway threshold, the pilot reduced power and extended the flaps to the third notch. Immediately following these control inputs, the airplane entered a stall condition. The subsequent impact with the runway surface was hard, resulting in damage to the aircraft.
The investigation
Post-accident examination confirmed that ice accumulation had occurred during the approach phase. The pilot's account indicated that visual reference to the runway was compromised by the whiteout conditions created by the snow cover on the ground.
Findings
The primary factors contributing to this accident were the aerodynamic stall of the airplane and the pilot's failure to maintain adequate airspeed during the final phase of the approach. Contributing to the severity of the event were icing conditions and reduced visual contrast due to snow cover.