AN ACR B737 FLC DSNDING ON A STAR GETS A TCASII RA TO CLB WHEN AN ACR MD80 CLBS THROUGH 7500 FT AS THE B737 DSNDS TO 7800 FT. THE CLB RA CHANGES TO INCREASE CLB AS THE MD80 CONTINUES ITS CLB. THE ACFT PASS VERY CLOSE TO EACH OTHER.

Narrative

CLRED TO DSND TO 7000 FT AT KAYOH INTXN FOR AN EASTSIDE ARR TO THE SNA ARPT. PASSING APPROX 8500 FT; CTR RPTED TFC AT 2 O'CLOCK; 8 NM CLBING THROUGH 7500 FT. WE RPTED NO CONTACT. AT 7800 FT TCASII ISSUED AN RA TO 'CLB.' THE CLB RA CONTINUED UNTIL APPROX 9000 FT WHEN 'INCREASE CLB' WAS ANNUNCIATED. WE INCREASED CLB AND ABOUT 10200 FT AN MD80 PASSED SLIGHTLY BENEATH OUR FLT PATH FROM ABOUT A 2 O'CLOCK POS. IMMEDIATELY AFTER PASSING TFC; WE WERE GIVEN A FREQ CHANGE TO APCH CTL AND CLRED TO DSND VIA THE 'EASTSIDE ARR.' DUE TO THE RA; WE WERE CONSIDERABLY ABOVE ALT FOR THE ARR. WE COMPLIED WITH THE ARR CONSTRICTIONS AS RAPIDLY AS POSSIBLE FOR A NORMAL APCH TO RWY 19R AT SNA. NEITHER PLT CAN ASCERTAIN WHY TCASII WOULD COMMAND A 'CLB' AND AN INCREASE CLB IN THIS SIT. FROM WHAT WE KNOW; IT APPEARS THAT A NORMAL OR 'INCREASE DSCNT' WOULD HAVE PROVIDED CLRNC. IT APPEARS TO US AS THOUGH WE CLBED INTO A CONFLICT. NO OTHER TFC WAS RPTED OR SIGHTED IN THE VICINITY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR SAID THAT HE HAD NEVER HAD A TCASII SYS TELL HIM TO INCREASE CLB BEFORE. HE SAID THAT HE WOULD HAVE BEEN BETTER OFF IF HE HAD CONTINUED HIS DSCNT; BUT NEITHER HE NOR THE TCASII KNEW THAT THE MD80 WAS GOING TO CONTINUE ITS CLB AND; IN FACT; INCREASE ITS CLB RATE. WHEN HE SAW THE MD80 CLBING TOWARD HIM WHILE HE WAS EVADING; USING A MAX PERFORMANCE CLB; HE WAS AFRAID TO TURN BECAUSE ANY ROLL WOULD HAVE LOST SOME OF HIS AVAILABLE LIFT AND HE FELT THAT THERE WAS NONE TO SPARE. HE SAID THAT HE COULD SEE EVERYTHING ABOUT THE MD80 AS IT PASSED; INCLUDING THE RIVETS. HE SAID THAT HE CALLED THE NUMBER THAT THE CTLR GAVE HIM FOR THE CTR. HE TOLD THE SUPVR THAT HE WAS THE CAPT OF THE B737-300 THAT HAD THE NMAC NEAR KAYOH. THE SUPVR; APPARENTLY; ADMITTED THAT THE CTLR ERRED AND WOULD RECEIVE FURTHER TRAINING ALONG WITH SEVERAL OTHER PERSONNEL. THE SUPVR SAID THAT THE ERROR WAS NOT DUE TO EQUIP PROBS; ACCORDING TO THE RPTR.