AT ABOUT 1600, THE ACFT WAS TAKEN OUT OF A HEATED HANGAR & PARKED ON THE RAMP FOR REFUELING. IT REMAINED OUTSIDE UNTIL THE PLT TOOK OFF AT ABOUT 1740 EST. DURING THAT TIME, SNOW WAS FALLING & THE TEMP DROPPED FROM 34 TO 31 DEG. THE PLT INITIALLY CONTACTED THE CONTROL TOWER FOR AN IFR CLEARANCE AT 1658, BUT HIS DEPARTURE WAS DELAYED DUE TO SNOW REMOVAL OPERATIONS. HE WENT INSIDE WHILE WAITING. AT ABOUT 1715, A CONTROLLER CALLED THE COMPANY OPERATIONS TO NOTIFY THE PLT THAT TAXI CLEARANCE COULD BE EXPECTED IN ABOUT 10 MIN. AT 1728:48, THE PLT CONTACTED TOWER FOR TAXI & IFR CLEARANCE, THEN ACKNOWLEDGED THE TAKEOFF CLEARANCE ABOUT 11 MINUTES LATER. SHORTLY AFTER TAKING OFF, THE AIRCRAFT CRASHED APRX 1 MI WEST & 3/4 MI SOUTH OF THE DEPARTURE END OF RWY 27. NO PREIMPACT PART FAILURE OR MALFUNCTION WAS FOUND. WITNESSES REPORTED SEEING THE ACFT IN A SHALLOW, LEFT TURN & DESCENDING BEFORE IT CRASHED. ONE WITNESS SAID IT WAS WALLOWING.