The Civil Aeronautics Board ( CAB ) investigated Criminal_investigation the accident Catastrophe and , after interviewing Communication numerous eyewitnesses and examining Testing the debris field , were able to conclude Coming_to_believe that the initial failure of the aircraft had begun Process_start in the left Departing wing .

The final report from the Civil Aeronautics Board , who conducted Action the investigation Scrutiny , stated , `` The Board has insufficient tangible evidence at this time to determine Deciding the cause of the accident . ''

Investigators with the Civil Aeronautics Board determined Deciding that the cable physically connecting Connect the first officer 's control wheel to the aileron boost unit had disconnected .

Investigators with the Civil Aeronautics Authority , a predecessor organization of both the FAA and the NTSB , determined Deciding that both vertical fins and both rudders were missing from the twin-tailed aircraft .

The Civil Aeronautics Board determined Deciding that the probable cause Causation of the accident was that the pilot , for undetermined reasons , deviated Change from departure course into an area of rising Cause_change_of_position_on_a_scale terrain , where downdraft activity and turbulence affected Influence the ability of the craft to climb Self_motion .

Investigators with the United States Department of Commerce 's Civil Aeronautics Authority ( CAA ) , a predecessor organization to both the FAA and the NTSB , determined Deciding that an intense fire had developed Coming_to_be in the cockpit shortly after the aircraft had departed Departing the airport .