THE FLT WAS CLRD FOR A LOC RWY 11 APCH. ABOUT 3 MIN LATER, THE 2ND-IN-COMMAND (SIC) RPRTD ' . . . WE DON'T GET THE LOCALIZER CAN YOU SEE IF WE'RE ON COURSE.' THE LAX ARTCC R-15 CTLR CONFIRMED THE FLT WAS RGT OF COURSE & BELOW THE RQRD ALT. THE ACFT'S MODE C INDCD AN ALT OF 1400 FT; THE CTLR ADZD THE FLT CREW TO MAINT AT LEAST 2300 FT UNTIL PAST THE FINAL APPROACH FIX (FAF). THE CREW THEN REPLIED THAT THEY WERE IN VMC. RADAR SVC WAS TERMINATED & A FREQ CHANGE TO TOWER WAS APPROVED. SHORTLY THEREAFTER, THE ACFT HIT A EUCALYPTUS TREE AT ABT 90 FT AGL, 2.05 MI FM THE APCH END OF THE RWY & ABT 195 FT RGT OF THE LOC. ELEV OF THE CRASH SITE WAS 101 FT; MIN DSCNT ALT (MDA) FOR THE APCH WAS 640 FT. THE 0645 PDT WX WAS, IN PART: INDEFINITE CEILING, 100 FT OBSCURED, VIS 1/8 MI WITH FOG, WIND FROM 220 DEG AT 4 KTS. NO PREIMPACT PART FAILURE OR MALFUNCTION OF THE ACFT WAS FOUND.