MULTIPLE RWY OP PARALLEL RWYS SIDEBY VISUAL APCH USE ACR X TCASII RA WITH ACR Y. EVASIVE ACTION TAKEN.

Narrative

ACR X APCHED SFO FROM N; ON RADAR VECTORS AND ASSIGNED IAS TO FINAL. NO APCH OR RWY ASSIGNED. AT 4000 FT ON SOUTHERLY HDG (210 DEGS); APCH CTL ASKED IF WE SAW AN ACFT AT 11 O'CLOCK. WE WERE LOOKING INTO THE SUN. NEITHER PF NOR PNF SAW ACFT. ATC GAVE US A HDG OF 280 DEGS TO DSND TO 2500 FT; AND ASKED IF WE SAW THE ARPT. I DID NOT CALL THE ARPT IN SIGHT AS DID NOT WANT TO ASSUME SEPARATION RESPONSIBILITY. JUST THEN TCASII ALERTED TO DSND AND I SPOTTED AN ACR Y MD88 OFF OUR L WING AT SAME ALT; APPROX 400-500 FT HORIZ. OTHER ACFT SEEMED TO MAINTAIN COURSE AND SLID TO OUR AFT L. I ADVISED ATC. ATC AGAIN ASKED IF WE SAW THE ACFT. WE TOOK EVASIVE ACTION TO THE R AND DOWN (AS TCASII DIRECTED) AND CALLED THE FIELD IN SIGHT. ATC THEN CLRED US FOR A VISUAL TO RWY 28R AT 160 KTS. ON SHORT FINAL THE ACR Y MD 88 WAS AGAIN ABREAST OF US RIGHT DOWN TO THE RWY; AND LANDED ON RWY 28L. THE PROB AROSE DUE TO ATC CONDUCTING SIMULTANEOUS APCHS TO 28L&R. IT IS AN INHERENTLY DANGEROUS OP. ATC IS COUNTING ON ACFT TO SEE AND CALL OTHER ACFT; THUS RELIEVING ATC OF SEPARATION RESPONSIBILITY. IT'S A BAD SIT FOR PLTS. THIS OP SHOULD BE STOPPED BEFORE A MIDAIR OCCURS. EVEN IF YOU THINK YOU SEE ANOTHER ACFT IT COULD BE THE WRONG ACFT; OR YOU COULD LOSE VISUAL SUDDENLY (E.G.; SUN IN YOUR EYES) CREATING A DANGEROUS SIT. SUPPLEMENTAL INFO FROM ACN 261302: I SAW THE TFC AT 10-11 O'CLOCK BUT WE WERE NOT COMFORTABLE WITH EXCEPTING THE VISUAL BECAUSE OF THE SUN AND THE CAPT AND FO DID NOT SEE THE ACFT. AT 2500 FT; HDG 280 DEGS AND ALIGNED WITH RWY 28L AND NOT ASSIGNED A RWY OR CLRED FOR APCH; THE TFC WAS VERY CLOSE TO OUR ACFT AND I TOLD CAPT AND FO (WHO WAS FLYING) THAT WE NEEDED TO MANEUVER AWAY FROM THE MD-80. WE GOT A TCASII 'DSND' ADVISORY AND THEN DEVIATED FROM 2500 FT ASSIGNED AND 280 DEGS ASSIGNED TO 2000 FT AND 260 DEG HDG. AFTER THE DEV WE CALLED THE ARPT IN SIGHT. AT THIS TIME WE WERE CLRED FOR THE VISUAL TO 28R. LNDG WAS UNEVENTFUL.