Accident Details
During the takeoff initial climb out, witnesses observed the airplane's wings rocking back and forth before it stalled and entered a spin, impacting terrain. A post-impact fire ensued. The airplane was occupied by a pilot, three passengers, luggage, miscellaneous items, and fuel. The exact amount of fuel on board could not be determined.
Weight and Balance
If the airplane had taken off with full fuel, it would have been over gross weight with the center of gravity outside the aft envelope. With 30 gallons of fuel on board, the airplane would have been within gross weight but still outside the center of gravity envelope (aft).
Injuries
The pilot and front seat passenger were fatally injured. The rear seat passengers survived.
Ice Accumulation
According to the rear seat passengers, on the morning of the accident the airplane was repositioned so that the sun could melt ice on the wings. After they ate breakfast and returned, a layer of 1/4- to 1/2-inch of ice still covered the airplane. The pilot and two passengers removed some ice from the wings and tail sections, but no ladders were used to remove ice from the tops of the wings. The weather conditions during the preceding 24 hours were conducive for the formation of frost, snow, and ice on the lifting surfaces. Numerous witnesses observed 1/4- to 1/2-inch of snow and ice on other airplanes parked at various spots on the airport that morning. Public deicing facilities were not available at the airport.
Mechanical Inspection
Investigators noted no mechanical discrepancies during the engine inspection that would have precluded it from producing power, and no discrepancies were found with the airframe.
Research on Ice Effects
Research has shown that frost, snow, and ice accumulations on the leading edge or upper surface of the wing, no thicker or rougher than a piece of coarse sandpaper, can reduce lift by 30 percent and increase drag up to 40 percent. Larger accretions of snow, ice, or frost can reduce lift even more and increase drag by 80 percent or more.
Toxicology
Toxicology testing of the pilot's blood detected a prescription antidepressant at a level consistent with routine use and an over-the-counter sedating antihistamine at a level above that expected from a single dose. The pilot had not reported the use of these medications to the Federal Aviation Administration.