THE ACFT WAS ABT 25 MI SOUTH & INBOUND TO DCA WHEN THE PLT RPRTD AN ENCTR WITH SNOWSHWRS WHICH WERE PART OF A COLD FRONT. HE ASKED & WAS CLRD TO DSCND TO 2500 FT SO HE COULD MAINT VMC. RADAR DATA SHOWED, THE ACFT DSCNDD PAST 2500 FT TO 1300 FT. ABT 16 MI SOUTH OF DCA, THE PLT SAID HE WAS REVERSING COURSE TO GET OUT OF THE SNOWSHWRS. HE ASKED & WAS CLRD TO CLIMB ON TOP OF THE WX, BUT (DUE TO TRAFFIC) WAS RESTRICTED TO 5500 FT. THE PLT ASKED TO GO TO THE NEAREST VMC ARPT; HOWEVER, RADIO CONTACT WAS LOST AFTER THE ACFT HAD CLIMBED TO 4600 FT. SUBSEQUENTLY, AN IN-FLT BREAKUP OCCURRED & WITNESSES SAW THE ACFT DSCND FROM THE CLOUDS IN PIECES. THEY SAID THERE WERE STRONG WINDS, SNOW & A LOW OVERCAST WHEN THE ACDNT OCCURRED. AN EXAM OF THE WRECKAGE REVEALED THE WINGS & STABILIZERS HAD SEPD IN FLT FROM OVERLOAD FAILURE. THE NON-INSTRUMENT RATED PLT WAS 1ST CHECKED OUT IN TYPE ACFT ABT 3 MOS EARLIER; SUBSEQUENT FLTS IN TYPE ACFT WERE MADE WITH AN INSTRUCTOR ABOARD. THIS WAS THE PLT'S 1ST FLT IN TYPE ACFT WITHOUT AN INSTRUCTOR ABOARD.