A B737-300 CAPT RPTED THAT SCT'S UNWILLINGNESS TO ISSUE AN APCH CLRNC TO LAX CAUSED THE CREW TO FIRST REACT TO A GPWS ALERT AND THEN TO A TCASII RA.

Narrative

APCH OFFERED VISUAL TO RWY 15 ON PRISTINE EVENING. ENJOYING EXCELLENT RAPPORT WITH FO (HIS LEG). HAD NOT SHOT THIS APCH IN NEARLY 10 YRS DUE TO PREVIOUS PROBS. PRIMARILY; TFC CONFLICTS OVER THE HILLS N OF ARPT AND PROBS BEING HIGH. DUE TO UNUSUALLY GOOD VISIBILITY IN THE VALLEY AND SEEMINGLY LITTLE TFC AND THE TERRAIN MAPPING FEATURE; I WAS NOT ADVERSE TO THE OPTION. I ASKED THE FO IF HE WANTED RWY 15 AND HE DID. WE WERE ON A 110 DEG HDG AND TOLD TO EXPECT APCH CLRNC IN 5 MI. WE WERE HEADING INTO RISING TERRAIN. WE WERE AWARE BOTH VISUALLY (SILHOUETTE) AND WITH THE TERRAIN FEATURE ON THE RADAR. WE WERE BECOMING INCREASINGLY ANXIOUS FOR APCH CLRNC. APCH HAD BECOME BUSY SINCE OUR INITIAL CALL. WE RECEIVED APCH CLRNC; ALBEIT LATE; AND THE FO BEGAN A TURN TO THE ARPT WHEN THE GPWS COMMANDED A CLB FOR TERRAIN. I TOOK THE ACFT AND INITIATED A CLB IMMEDIATELY. I GAVE THE ACFT BACK TO THE FO; BUT WITHIN SECONDS; THE TCASII ALERTED US TO CLB AT 1500 FPM. SIMULTANEOUSLY; ATC WAS ALERTING US TO TFC HEAD ON; OPPOSITE DIRECTION. A GULFSTREAM 5 WAS INBOUND TO VAN NUYS FROM E OF BURBANK. WE PASSED 300-500 FT DIRECTLY ABOVE THE G5. WE SAW HIM AND HE SAW US AS HE COMMENTED ON FREQ THAT WE WERE 'DOING GOOD.' I AGAIN RETURNED CTL OF THE ACFT TO FO AND ASKED TO BE SEQUENCED FOR RWY 8 AT THIS TIME. WE LANDED SAFELY AND I MADE PA AT GATE DESCRIBING WHAT HAPPENED. IN HINDSIGHT; I WILL NO LONGER USE RWY 15 (PARTICULARLY AT NIGHT) UNLESS OPERATIONALLY REQUIRED. THE FACT THAT WE HAVE TO RESPOND TO GPWS COMMANDS AT NIGHT MAKE IT UNWISE. PERHAPS ATC SHOULD REVISE PROCS SO AS NOT TO PLACE ACFT ON HEADING INTO TERRAIN PENDING APCH CLRNC. IF THEY CANNOT CLR FOR APCH EARLY; THEN THEY SHOULD CONSIDER CANCELING THE APCH AND TURNING ACFT W FOR RESEQUENCE. WHILE NOT CONFIRMED; I SUSPECT THE G5 CONFLICT MAY HAVE BEEN THE REASON FOR THE DELAY OF APCH CLRNC. P.S. MULTIPLE CALLS MADE TO ATC SPECIALIST AND NO RETURNED CALL?!