NTSB Probable Cause

1) A PARTIAL LOSS OF THE AIRPLANE'S VACUUM SYSTEM WHICH RESULTED IN THE TOTAL LOSS OF THE DIRECTIONAL GYRO AND THE ATTITUDE INDICATOR, 2) THE PILOT NOT MAINTAINING AIRCRAFT CONTROL DUE SPATIAL DISORIENTATION, AND 3) THE PILOT NOT CORRECTING FOR A SPIRAL BY USING PROPER RECOVERY TECHNIQUES WHICH RESULTED IN THE OVERLOAD FAILURE OF THE WINGS. A FACTOR IN THE ACCIDENT WAS THE PILOT'S LACK OF TOTAL INSTURMENT FLIGHT EXPEREINCE.