The airplane was loaded with 10 sport parachutists and one pilot. Later, investigators calculated that the maximum gross weight was exceeded by 149.6 pounds, and the center of gravity was 2.87 inches aft of the aft limit. The cabin door had been removed for parachuting operations; however, an altered Flight Manual Supplement had been used as authority for the door removal.
After takeoff, the airplane was seen at low altitude trailing smoke from the left engine. Witnesses saw the wings ‘tipping’ back and forth, then a wing dropped and hit the ground. Examination revealed that a supercharger bearing had failed in the left engine. The left engine had been recently installed by non-certificated personnel after being inactive for 18 yrs without preservation.