NCT CTLR DESCRIBED OPDEV EVENT CLAIMING CHANGING FROM ONE RADAR SYSTEM TO ANOTHER CAUSED LOSS OF TARGET THAT RESULTED IN OPDEV.

Narrative

WHEN CHANGING FROM ONE RADAR SITE TO ANOTHER; ACFT WITH ARTS DATA TAGS FROM JUST OVER 60 MI AWAY TO JUST UNDER 62 MI AWAY FROM THE RADAR SITE WILL DROP FROM THE SCOPE AND SYS. MORE THAN 62 THEY STAY ON SCOPE AS 'OR' OR OUT OF RANGE; 60 OR LESS AND THEY WILL 'COAST' AND REACQUIRE. ACFT WAS NEBOUND ON V332 AT 10000 FT MSL ON AN IFR FLT PLAN. AN AUTOMATED HDOF WAS ACCOMPLISHED TO THE PARADISE SECTOR AT NORCAL TRACON (NCT). PARADISE IS A VERY LARGE SECTOR AND CAN USE 2 ASR RADAR SITES (MCCLELLAN MCC AND BEALE BAB). CTLR WAS USING MCC RADAR AND CHANGED FROM MCC TO BAB TO CHK AN ALT ON AN ACFT AT HIS N BOUNDARY (POOR COVERAGE ON MCC N; POOR COVERAGE S ON BAB). AT THAT TIME THE C210 WAS 60-61 MI FROM THE BAB RADAR SITE AND THE DATA TAG DROPPED FROM THE RADAR/ARTS AND DID NOT REACQUIRE. CTLR WAS WORKING SEVERAL OTHER ACFT AT THAT TIME. I ASSUMED THE POS APPROX 10 MINS LATER AND WAS NOT INFORMED OF THE C210. THE ACFT FLEW THROUGH PARADISE'S AIRSPACE AND INTO ZOA SECTOR 42 WITHOUT A HDOF. FAA HAS SINCE TRIED TO 'FIX' THE RADAR/ARTS SO ACFT DATA TAGS WILL NOT DROP FROM THE SCOPE.