What happened
During a flight traveling from Sacramento to Portland, a twin engine airplane was operating at cruising altitude amidst challenging weather conditions. While navigating through marginal visibility and precipitation, the aircraft experienced a structural failure of the airframe. This failure caused the plane to enter an uncontrolled dive, ultimately impacting a field situated near Cheshire, northwest of Eugene. The impact resulted in the total destruction of the aircraft and seven fatalities.
Findings
Investigations into the accident identified several critical contributing factors that led to the structural failure and subsequent crash. The aircraft was operating in icing conditions characterized by sleet and freezing rain, which resulted in the accumulation of ice on the airframe. Furthermore, the plane lacked necessary anti-icing or de-icing equipment for such environments.
Several operational errors were also noted during the investigation:
- The aircraft's weight and balance were improperly managed, with the plane being approximately 790 lbs above its maximum allowable takeoff weight.
- The structural stress limits of the airframe were exceeded.
- There was evidence of inadequate preflight preparation and improper loading regarding the center of gravity.
- The flight was conducted in visibility of less than two miles.
- The aircraft exceeded its designed stress limits due to a combination of weight, icing, and flight maneuvers.