Accident Overview
During cruise at an altitude of 8,000 feet, the aircraft encountered foggy and icing conditions. Both engines number three and four subsequently failed. The flight crew attempted to restart the engines but was unsuccessful.
Sequence of Events
Following the engine failures, the airplane went out of control and plunged before impacting a wooded area. The aircraft struck the ground in a level attitude with no forward velocity. The impact resulted in the destruction of the aircraft.
Damage and Fatalities
The airplane was destroyed. All 50 occupants on board were killed.
Probable Cause
The official investigation determined that the probable cause of the accident was the delayed arming of the engine ice-protection systems while flying in icy conditions, resulting in the loss of engine power and attendant electrical energy required to unfeather propellers and relight sufficient engines to maintain flight.