WAKE TURB ENCOUNTER DUE TO XING ARR RTES.

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I HAVE BEEN FLYING THESE RTES FROM S FLORIDA TO AND FROM THE BAHAMA ISLANDS FOR APPROX 7 YRS IN C402'S. IN THIS TIME; I HAVE HAD 3 DEFINITE WAKE TURB ENCOUNTERS AND NUMEROUS SUSPICIOUS 'BUMPS' ON THIS ARR INTO THE FLL/MIA AREA. THE CTR CLRS ALL LIGHT TWIN AND SLOW TFC TO 6000 FT AND ALL JET/FAST ACFT TO 7000 FT IN THE VICINITY OF MRLIN INTXN. WE OFTEN CROSS PATHS AT MRLIN; THE SLOWER ACFT THEN FOLLOWING THE LARGE TRANSPORTS DOWN 68V (SW) INTO THE FLL TFC PATTERN. NATURALLY THE LARGE ACFT PULLS AHEAD; WHEN ENOUGH SEPARATION OBTAINED; (USUALLY ABOUT 5- 10 MI NE OF FLL) THE LARGE ACFT IS DSNDED TO 6000 FT; TURNED R (WBOUND); THEN DSNDED TO 4000 FT AND ON INTO THE APCH FOR RWY 09L FLL. THE LIGHT SLOW TFC FOLLOWS; OFTEN GETTING DSCNT CLRNC AFTER THE LARGE ACFT AT FLT PATHS OFTEN CROSS; INTERSECTING ALTS. IN OTHER WORDS; THE LIGHT ACFT FLIES THROUGH THE SAME PLACE AS A LARGE ACFT; THROUGH ITS 'WAKE PATH;' USUALLY WITHIN 10 MI. APCH WILL ADVISE OF TFC; HOWEVER; ESPECIALLY IN IMC CONDITIONS; THE LIGHT ACFT IS STILL RESTR TO FLY THE SAME ARR. (DUE TO GEOGRAPHICS; THERE IS NOT A LOT OF ROOM TO WORK WITH HERE). FOR EXAMPLE; ONE MEMORABLE ENCOUNTER. AT ABOUT 30 DME FROM FLL; APCH ADVISED OF HVY L1011 TFC PASSING 1000 FT OVERHEAD; SAME DIRECTION. I VISUALLY CALLED TFC AND WATCH HIM OUT OF SIGHT. WITH APCH DUTIES; I FORGOT ABOUT HIM. AT ABOUT 10 DME FROM FLL; I ENCOUNTERED THE WAKE. IT WAS A HARD ROLL; L; ABOUT 60 DEGS BEFORE I COULD STOP IT. (IT WOKE THE PAX). I QUERIED THE APCH CTLR. SHE TERSELY REMINDED ME SHE HAD INFORMED ME AND I HAD CALLED THE TFC IN SIGHT. ON INFORMING HER I HAD UNEXPECTEDLY HIT THE WAKE; SHE CONFIRMED THE TFC WAS 10 MI AHEAD. I ESTIMATE OUR SPD DIFFERENCE AT 90 KTS. THIS WOULD MEAN APPROX 9 MINS ELAPSED; WITH 1000 FT VERT SEPARATION; BEFORE MY FLT PATH INTERSECTED THE L1011'S 'WAKE PATH.' I FEEL THE POTENTIAL FOR MORE ENCOUNTERS IS THREATENING. IF I HAVE HAD NUMEROUS ENCOUNTERS; AND I AM ONLY ONE OF MANY INBOUND (EVEN ONE OF MANY COMMUTER FLTS); THERE MUST BE MORE ENCOUNTERS OCCURRING. I FEEL THE LIGHT/SLOW TFC SHOULD HAVE A DIFFERENT ARR; IF ONLY BY A FEW DEGS; AND PERHAPS A LOWER ARR ALT TO SEPARATE AND LESSEN THE NUMBER OF TIMES WE INTERSECT FLT PATH COURSES WITH LARGE ACFT. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: RPTR PARTICIPATED IN WAKE TURB CALLBACK QUESTIONNAIRE. SHE HAD BEEN FLYING THIS RTE FOR 7 YRS AND WAS WELL AWARE OF THE WAKE PROBS AT FLL. SHE RECOMMENDS A SECOND ARR RTE FOR SMALL ACFT.