CL65 CREW GOT THE ENHANCED GPWS WARNING WHILE ATTEMPTING A NIGHT VISUAL APCH TO RWY 25 AT SBA.

Narrative

WHEN ON THE VOR APCH TO RWY 25 AT SBA; WE (THE CREW) GOT TERRAIN CAUTION MESSAGE. THIS HAPPENED INSIDE THE FAF. I LEVELED OFF AND THE CAUTION MESSAGE CLRED. I THEN CONTINUED TO DSND TO THE MDA AND RECEIVED THE CAUTION MESSAGE ONCE AGAIN; SO I STOPPED THE DSCNT AND THE CAUTION CLRED. PRIOR TO REACHING THE MAP 14.7 AT MARNS FROM GVO VOR; TERRAIN MASTER WARNING ALERT; WE (THE CREW) IMMEDIATELY EXECUTED A MISSED APCH PROC. THE CAPT THEN REESTABLISHED COMS WITH ZLA; ADVISED WE WENT MISSED AND REQUESTED VECTORS TO ILS; WHERE WE LANDED WITH NO FURTHER INCIDENT. BACKGROUND PRIOR TO VOR APCH. ATIS: 10 SM CLR WINDS CALM. TWR: CLOSED; ZLA ADVISED TO CONTACT CTAF ON APCH. WE BEGAN OUR DSCNT FROM 12000 FT TO 5000 FT XING OVER THE SANTA YNEZ MOUNTAINS. ZLA WANTED TO KNOW WHEN WE HAD THE FIELD IN SIGHT; WE DID NOT. WE ALONG WITH CTR WERE EXPECTING TO SEE THE FIELD BECAUSE FIELD CONDITIONS WERE CALLING VFR. WHEN WE GOT DOWN TO 5000 FT WE COULDN'T SEE THE FIELD; WE HAND FLEW UP THE COASTLINE AND REQUESTED CTR FOR VECTORS TO THE FIELD; WHEN IT WAS APPARENT THAT WE COULDN'T SEE THE FIELD WE DECIDED ON THE VOR RWY 25 APCH. WE WERE VECTORED DOWNWIND ALONG THE COASTLINE AND CLRED TO WANG FOR THE VOR RWY 25 APCH. WHILE ON THE APCH PHASE THE AUTOPLT DISENGAGED; SO I HAND FLEW THE APCH FROM THAT POINT. THE REST IS AS STATED ON THE FRONT. PROBABLE CAUSE OF PROB: 1) EXPECTING TO GET A VISUAL APCH INITIALLY BECAUSE ATIS/AWOS WAS CALLING CLR. 2) IN ACTUALITY THERE WAS A MARINE LAYER INLAND ON THE APCH END OF RWY 25 OBSCURING US FROM SEEING THE FIELD. THE COASTLINE WAS CLR. 3) AUTOPLT DISENGAGED. PREVENT FUTURE OCCURRENCE: 1) SINCE CALM WINDS PREVAILED; SHOULD HAVE OPTED FOR ILS RWY 7 FROM THE START. 2 ) SHOULD HAVE SLOWED ACFT PRIOR TO BEGINNING DSCNT FROM 12000 FT TO 5000 FT.