Date: 201511
Local time of day: 1801-2400
Location: SCT.TRACON, CA
Light: Night
Aircraft: Amateur/Home Built/Experimental
Flight plan: IFR
Flight phase: Cruise
Airspace: Class E ZLA
ATC / advisory: TRACON SCT
Second aircraft: Small Aircraft; Low Wing; 1 Eng; Retractable Gear
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Troubleshooting; Human-Machine Interface; Distraction; Confusion; Workload
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
Result: Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance
Contributing factors: ATC Equipment / Nav Facility / Buildings; Human Factors; Procedure
Primary problem: ATC Equipment / Nav Facility / Buildings

Narrative: First let me say that I am filing this report to document along with safety problem; there was no loss of separation. Aircraft X IFR departed CNO direct to PDZ VOR climbing to 040 to join V186 which is the PDZ 130R climbing to altitude 040.  Aircraft Y IFR inbound to CNO from the southwest; direct PDZ; instructed to depart PDZ heading 090; level at altitude 050.  Traffic was issued to both aircraft.  I observed Aircraft X primary target pass behind Aircraft Y just south of the PDZ VOR.  Using diverging courses; I then climbed Aircraft X to altitude 070.  It was then that I noticed the primary target for Aircraft X turn east bound and parallel Aircraft Y who was still on a 090 heading level at altitude 050.  I frantically told Aircraft X to descend back to 040; to try and maintain separation.  Then Aircraft X primary target went to NAT; (Not ARTS Tracked) then magically appear to be established on V186 southeast bound; out of 44 descending back to altitude 040.  I then issued the climb again to Aircraft X and shipped the aircraft.  The whole ordeal lasted approximately four (4) seconds.  This is not the first time something like this has happened; and our local managements reply is to simply; log the problem and we will look into it.Shut down Standard Terminal Automation Replacement System (STARS) which is having several problems; especially when it comes to its integration with fusion or stop using fusion and go to single sensor.  It is unfair to us as controllers; to go from a perfectly working system Common Automated Radar Terminal System (ARTS); to a buggy; problem riddled system such as STARs due from pressure from local management to get this implicated.  There have been many; many problems with STARs implementation; and from the get go managements stance has always been 'It's staying on unless there is a critical error'.  In order to efficiently separate aircraft; we need to use all the tools available to us via the 7110.65; but how are we supposed to ensure positive separation with a system that is not 100 percent accurate in display aircraft courses; even if it's only for 4 seconds.




Synopsis: A SCT TRACON Controller reported of a FUSION Radar tracking problem.  The Controller reported of a track that turned to parallel another aircraft that he was separating the turning aircraft from.  The Controller reported the STARS system showing Not ARTS Tracked (NAT) on the aircraft then it jumped back to where it was originally supposed to be flying.  Controller wants the STARS turned off and Common Automated Radar Terminal System (ARTS) used again.