NTSB Probable Cause

THE PILOT-IN-COMMAND'S IN FLIGHT LOSS OF CONTROL DUE TO SPATIAL DISORIENTATION. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT-IN-COMMAND'S LACK OF TOTAL EXPERIENCE IN NIGHT FLIGHT, AND THE LACK OF NATURAL HORIZON OR SURFACE REFERENCE WHILE FLYING OVER A SPARSELY POPULATED AREA ON A DARK NIGHT.