FAILURE OF THE PILOT TO MAINTAIN CONTROL OF THE AIRCRAFT AFTER BECOMING SPATIALLY DISORIENTATED IN NIGHT INSTRUMENT METEOROLOGICAL CONDITIONS (IMC). FACTORS RELATED TO THE ACCIDENT WERE: THE PILOT'S LACK OF EXPERIENCE IN THE TYPE OF OPERATION, HIS LACK OF RECENT INSTRUMENT EXPERIENCE, AND INADEQUATE SURVEILLANCE OF THE OPERATION BY THE CHIEF PILOT/COMPANY MANAGEMENT.