AN ACR MD80S ON VISUAL APCH AND ADVISED OF TFC TO THE L WHO IS LNDG ON PARALLEL RWY. OTHER ACFT OVERSHOT CTRLINE WHICH REQUIRED RPTR TO TAKE EVASIVE ACTION. RPTR CAPT SAYS SIDE-BY-SIDE APCHS WHEN ONE ACFT IS TURNING IN ON FINAL IS A SETUP FOR CONFLICT.

Narrative

ON CIVET ARR; WAS CLRED FOR VISUAL APCH TO RWY 25R; AND ADVISED WOULD HAVE TFC FROM S FOR RWY 25L. AT APPROX 13 NM; ACR B727 HOOKED IN FROM S FOR RWY 25L; AND HAD SOLID VISUAL CONTACT WITH TFC. WHILE TRACKING THE RWY 25R LOC; KEPT B727 IN SIGHT FROM ABOVE AND JUST AFT ON R SIDE OF B727. FROM MY POS; IT LOOKED AS IF ACR WAS NOT EXACTLY TRACKING THE CTRLINE OF RWY 25L. AFTER CHK-IN WITH TWR ON 120.95; AT APPROX 5 NM; THE B727 STARTED TO DRIFT SLIGHTLY R AND ALTER HIS GLIDE PATH TO WHAT MIGHT HAVE BEEN A GAR MANEUVER. THIS DRIFT CAUSED ME TO DISCONNECT AUTOPLT AND COME R TO INCREASE DIMINISHING LATERAL SEPARATION. B727 ASKED TWR IF THEY WERE CLRED TO LAND AS IF THEY WERE CONFUSED. TWR AGAIN RECONFIRMED THAT HE WAS CLRED FOR RWY 25L AND WE WERE CLRED FOR RWY 25R. I THEN HAD TO COME BACK TO THE L TO RE-ESTABLISH THE CTRLINE FOR RWY 25R AND SUBSEQUENT UNEVENTFUL LNDG WAS MADE. I STRONGLY RECOMMEND THAT SOCAL APCH NOT USE THIS PROC IF THERE IS ANY DOUBT AS TO WHAT IS HAPPENING. THIS COULD HAVE GOTTEN VERY UGLY.