What happened
On December 23, 1984, a private aircraft crashed into the ground near the airport at Billings, Montana, killing all three occupants onboard. The pilot was not instrument rated but had filed an IFR flight plan and received prior weather briefings before departure. Weather conditions at the time included an indefinite ceiling of 100 feet, sky obscured, one-half mile visibility, snow, and fog. Shortly after takeoff, radar indicated the aircraft was meandering over the airport. Local witnesses heard the plane make a couple of spiral-type turns before impact.
The investigation
Examination of the wreckage revealed that the vertical stabilizer, horizontal stabilizers, and right wing separated in flight just prior to impact with the ground.
Findings
The pilot was not instrument rated yet flew into instrument meteorological conditions. The aircraft experienced structural failure of the empennage and right wing during flight.