WAKE TURB ENCOUNTER ON FINAL APCH AT ATL.

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WAKE TURB ENCOUNTER (MINOR; 20 DEG ROLL MAX). WE TURNED 14 MI FINAL ON THE ILS LOC FOR RWY 27L ATL AT 3500 FT MSL. ATC POINTED OUT A B737 TURNING BASE TO FINAL 4 MI AHEAD OF US; DSNDING OUT OF 6000 FT AND CLRED US FOR THE VISUAL APCH. I EXPECTED; AND WE DID ENCOUNTER SOME WAKE WHEN WE REACHED THE POINT WHERE THE OTHER ACFT HAD DSNDED THROUGH OUR ALT. I HAVE SEEN THIS BEFORE; AND WILL OFTEN ASK FOR A SLIGHT HDG CHANGE TO OFFSET MY FLT PATH. I FEEL THAT THE ISSUE OF ACFT ALT; PARTICULARLY WHEN A LARGER ACFT DSNDS THROUGH THE ALT OF THE FOLLOWING ACFT'S ALT; NEEDS TO BE ADDRESSED. IN ATL; FOR INSTANCE; TURBOPROP ARRS ARE TURNED ON THE DOWNWIND LEG 1000 FT BELOW THE JETS; SO AT SOME POINT IN TIME AS THE JET DSNDS AHEAD; THE FLT PATHS MUST CROSS AND THE POSSIBILITY FOR A WAKE ENCOUNTER EXISTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: PLT PARTICIPATED IN THE STRUCTURED CALLBACK WAKE TURB PROGRAM. PLT WANTED TO FLY INTO THE WAKE OF THE PRECEDING B737 TO SEE JUST HOW MUCH ITS WAKE AFFECTED HIS ACFT. BECAUSE OF THE DISTANCE AND THE TYPE OF ACFT HE WAS FOLLOWING; THE UPSET WAS NOT GREAT. HE ROLLED ABOUT 20 DEGS AND LOST 50 FT. TO HIM IT WAS COMFORTING THAT THE B737 WAS MINOR IN INTENSITY. IT DID PROVE TO HIM THAT HIS CONCERN REGARDING THE DSCNT OF BIGGER ACFT DOWN THROUGH HIS ALT WILL ALWAYS PRODUCE A WAKE TO BE ENCOUNTERED. HE FEELS SOME PROC SHOULD BE DEVELOPED TO MOVE THE FOLLOWING ACFT AWAY FROM THE WAKE BY DISTANCE OR HEADING CHANGE.