Accident
The aircraft was observed flying slowly shortly after takeoff. It then rolled steeply to the left and descended into an unoccupied house from an altitude of about 300 feet. The collision resulted in the death of all five occupants.
Pilot and Passenger
The pilot had considerable flight experience but had flown this specific model only during a 35-minute checkout earlier that morning, which consisted of three takeoffs and landings. A friend, who was a rated pilot but lacked a multi-engine rating, occupied the right cockpit seat. This friend had logged flight time in the pilot's other twin-engine aircraft. A witness reported that the pilot appeared pale and troubled just before the flight.
Medical Examination
An autopsy of the pilot revealed that the left main coronary artery was blocked except for a pinhole opening. The examining doctor stated that this condition could have caused a seizure but could not determine whether it was a factor in the accident.
Weight and Balance
No evidence was found of any preimpact malfunction or failure of the airframe, propellers, or engines. However, the aircraft was estimated to be 134 pounds over its maximum gross weight at the time of the accident.
Probable Cause
The official probable cause was loss of control during the initial climb due to an inadvertent stall. Contributing factors included the pilot's failure to maintain airspeed, operation of the aircraft exceeding weight and balance limits, and physical impairment (cardiovascular condition).