B737-300 FLT CREW ON APCH TO BUR FAILED TO FOLLOW THE CHARTED VISUAL APCH PROCS.

Narrative

ON APCH INTO BUR WE WERE CLRED FOR VISUAL APCH TO RWY 15. WE WERE AT 5000 FT IN THE VICINITY OF OAT MOUNTAIN. THE CAPT BRIEFED HE WOULD FOLLOW THE PROFILE ON FOUR STACKS VISUAL APCH (IE; 5000 FT UNTIL PASSING OAT MOUNTAIN; THEN 3000 FT UNTIL FINAL). AS WE DSNDED TO 3000 FT INSIDE SAN GABRIEL MOUNTAINS; HE STARTED A DOGLEG BASE TO FINAL. I SAID; 'WHITEMAN ARPT IS RIGHT THERE. DO YOU SEE IT?' HE SAID HE SAW IT. ABOUT THAT TIME HE TURNED OFF THE AUTOPLT AND BEGAN ASKING FOR CONFIGN FOR LNDG. NEXT I NOTICED WE WERE 2200-2500 FT MSL STILL ANGLED OVER WHITEMAN. I SAID WE NEED TO MAINTAIN 3000 FT OR WE'LL BE IN THEIR AIRSPACE. ABOUT THAT TIME WE RECEIVED AN RA TO MONITOR VERT SPD. HE ACKNOWLEDGED AND COMPLIED WITH RA. WE THEN RECEIVED A TA. I CALLED OUT TFC AND SAW WE WERE STILL DSNDING. I REITERATED WE WERE TOO CLOSE TO WHITEMAN. HE ACKNOWLEDGED AND LEVELED OFF. AT THIS TIME; TWR TOLD US FOR FUTURE REF THEY NEEDED US TO FLY AN EXTENDED CTRLINE FINAL AND NOT A DOGLEG. THE CAPT CALLED TWR ONCE ON THE GND. THEY INSURED THE CAPT THERE WAS NO FURTHER PROB; BUT TO MAKE SURE TO FOLLOW THE CHARTED FINAL.