NYC83FA121

The acft collided with the ground in IMC after the plt reported he lost his vacuum instruments. The flt originated at mattituck, NY with a destination of lebanon, NH. After departure the plt was cleared to climb to 7000 ft. the instrumentrated pilot was on an IFR flt plan. About 8 minutes after departure the pilot radioed that he had experienced a loss of vacuum and his artificial horizon was inoperative. He also stated he had no autopilot and requested radar vectoring. He was given a heading of 050 for radar vectoring to norwich VOR. About 2 minutes later the pilot radioed he was 'in trouble and in a dive.' One min later he radioed 'one thousand ft I am in deep trouble here.' This was the last radio call from the plt. Witnesses in the area heard & saw the acft come out of the clouds at 200-300 ft & then climb back into the fog bank. Shortly thereafter, a 'whistling dive' was heard followed by the sound of a crash. The wx in that area was described as fog, light rain, & overcast. Exam of the acft wreckage revealed that the vacuum pump failed.