THE PILOT'S LOSS OF AIRCRAFT CONTROL DUE TO SPATIAL DISORIENTATION AFTER ENCOUNTERING INSTRUMENT METEOROLOGICAL WEATHER CONDITIONS (IMC) SHORTLY AFTER TAKEOFF, HIS INTENTIONAL TAKEOFF INTO ADVERSE WEATHER CONDITIONS, AND THE OPERATOR'S INADEQUATE SUPERVISION OF CONTROLLING ACCESS TO THEIR AIRPLANES BY STUDENT PILOTS IN KNOWN ADVERSE WEATHER CONDITIONS. FACTORS CONTRIBUTING TO THE ACCIDENT WERE THE WEATHER CONDITIONS, THE PILOT'S FAILURE TO OBTAIN A WEATHER BRIEFING, AND HIS LACK OF INSTRUMENT FLIGHT TIME.