C560 EXPERIENCES NMAC ON VISUAL APCH TO DVT.

Narrative

WE DEPARTED ON AN IFR FLT PLAN; WITH DVT AS DEST. OWNER/PF WAS OCCUPYING THE L SEAT. RPTR (PIC) WAS ACTING AS PNF. WE HAD PROCEEDED ON THE JACBS2 ARR AND WERE EVENTUALLY TOLD TO DSND TO 4000 FT AND PROCEED TO THE ARPT AND CALL IT IN SIGHT. THIS CALL WAS MADE ABOUT 7 MI OUT AND CLRNC FOR A VISUAL APCH TO RWY 25L GIVEN AND INSTRUCTIONS TO CHANGE TO THE N SIDE TWR FREQ AND ATTN CALLED TO ANOTHER TFC AT OUR 9 O'CLOCK POS. OUR TCAS WAS PICKING UP THIS BOGEY AND SHOWING IT ABOUT 300 FT BELOW US. THE PF BEGAN A L TURN AND LEVELED OFF INTO A SLIGHT CLB (WE HAD ALREADY BEGUN OUR DSCNT) AND AS I WAS ABOUT TO CONTACT THE TWR WHEN I VISUALLY SAW THE OTHER TFC; FLYING EBOUND AND ON AN EXACT COLLISION COURSE WITH US AND INSTANTLY GRABBED THE CTL WHEEL AND BRISKLY PULLED US UP INTO A VERY STEEP CLB AND SECONDS LATER HEARD THE SOUND OF THE PROP(S) PASSING JUST UNDERNEATH US. ONLY THEN WAS THERE TIME TO COMMUNICATE WITH THE CTL TWR; WHICH IN TURN SWITCHED US TO THE S SIDE FREQ; FOLLOWED BY LNDG INSTRUCTIONS. THE TWR WAS LATER CONTACTED BY PHONE. IT CAN ONLY BE SPECULATED THAT THE OTHER AIRPLANE WAS ALSO CLBING. THE TCAS ON THIS CITATION V DOES HAVE A DISPLAY LAG OF SORTS.