A B757-200 FLC DOES NOT MAKE THE REQUIRED 30 DEG TURN ON THEIR DEP SID OUT OF LAX; CA.

Narrative

WHILE SITTING AT GATE (LAX) LOCATED 50 YARDS FROM THE DEP END OF RWY 24L; MY FO BRIEFED THE DEP PROC FOR RWY 24L (WHICH WAS THE DEP RWY EVERY TIME FOR ME IN THE LAST 4 YRS OPERATING OUT OF LAX). THAT PROC IS A STRAIGHT OUT CLB ON A 250 DEG HDG AFTER TKOF. WITHOUT ANY WARNING; LAX GND CTL ISSUED A TAXI CLRNC TO THE OPPOSITE SIDE OF THE ARPT USING THE 'S TAXI RTE.' AS I HAD NEVER DEPARTED FROM THE S COMPLEX AT LAX (RWY 25L/R) I WAS UNFAMILIAR WITH THE PROC AND REQUESTED MY FO TO HELP LEAD ME THROUGH THE TURNS; RTE; ETC. GND MOVEMENT OF ACFT WAS SATURATED WITH NON STOP RADIO COM. I WAS GIVEN 10-15 ADDITIONAL TAXI INSTRUCTIONS CONCERNING OTHER ACFT AND THERE WAS AT LEAST THAT MANY INSTRUCTIONS TO OTHER ACFT GETTING THEM CLR OF OUR RTE. THERE WERE ACFT MOVING FROM LITERALLY EVERY DIRECTION AND MY FO AND MYSELF WERE TOTALLY FOCUSED ON THE JOB AT HAND. EVEN WHILE THE NON STOP RADIO TALK WAS GOING ON; I CALLED FOR THE 'BEFORE TKOF CHKLIST' AND I TRIED TO LISTEN TO MY FO AND ALL THE RADIO XMISSION SIMULTANEOUSLY. WHEN THE TKOF BRIEF CAME UP IN THE CHK; MY FO HAD THE DEP PAGE IN FRONT WHILE I REMAINED GLUED TO THE ARPT/TAXI CHART AND THERE WAS A COMMUTER GETTING SPECIFIC INSTRUCTIONS ON HOW TO TAXI TO A RTE AROUND US AT THE SAME MOMENT OF THE DEP BRIEF. THIS RADIO XMISSION CAUGHT THE ATTN OF MY FO AND HE MISSED THE 30 DEG L TURN ON THE CHART AND I DIDN'T CATCH THE OVERSIGHT. BY THE TIME WE GOT TO THE RWY; WE HAD BEEN 38 MINS SINCE WE LEFT THE GATE (ACCORDING TO OUR ACARS). WE TOOK OFF FROM RWY 25R AND DID NOT MAKE THE TURN TO 220 DEGS. EVEN THOUGH WE CONTACTED SOCAL DEP AT 700 FT AGL 10 SECONDS AFTER LIFTOFF; THEIR FIRST TURN FOR US WASN'T FOR 2-3 MINS. MOST EVERY HIGH DENSITY ARPT IN AMERICA GIVES PLTS A 'HEADS UP' TYPE OF INFO TO LET PLTS PLAN FOR AN ANTICIPATED PROC. LAX ATC CHANGES 'THE PLAN' WITHOUT NOTICE MANY; MANY TIMES MORE THAN ANY OTHER TERMINAL ARPT. IF WE HAD ANY NOTICE THIS HIGHLY IRREGULAR DEP RWY WS GOING TO BE USED; THEN WE WOULD'VE BEEN ABLE TO DEAL WITH THE TAXI AND DEP PROCS SEPARATELY AND WOULD NOT HAVE MISSED NOTING THE TURN ON THE DEP.