NYC85FA141

Plt filed IFR for 2 flight legs; baltimore, MD to teterboro, NJ & teterboro to montgomert, NY (orange co arpt). The plt received a preflight wx briefing & was advised that the forecast for stewart, NY, about 10 mis form montgomery was sky partially obscured 4000', 500' scattered & 4 mis in fog. While enroute to teterboro, at 0134 hrs, theplt radioed stewart arpt & was advised of wx there as sky partially obscured with 4 mis in fog & haze. The acft landed at teterboro at 0152 hrs and departed VFR at 0200 hrs. At 0211 hrs the plt radioed another acft & in part stated that he was at orange co arpt & was attempting to land, however the wx was going down. At 0211 hrs the plt radioed stewart & was advised that wx there was the same as reported at 0134 hrs. The plt acknowledged. There was no further transmx from the plt. At 0215 hrs a witness near the acc site heard a crash. He reported wx as 400' in fog. The acft crashed 2 mis south of rwy 03. The lndg gear & flaps were down. Examination of the acft did not disclose evidence of malfunction.