Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 6
Communication Breakdown; Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic
Environment - Non Weather Related; Airport; Aircraft; Human Factors; Procedure
Aircraft X was enroute and was cleared ILS Approach. A VFR 1200 code target tracking east of the localizer northbound climbing slowly. I called traffic to Aircraft X several times but they were unable to get a visual on the 1200 code. I canceled Aircraft X's approach clearance and assigned 9000 feet. The VFR target began to turn to cross the localizer and toward Aircraft X and so I turned Aircraft X 10 degrees right. The targets were close; about 600 feet and about 1 mile lateral. Aircraft X reported the traffic in sight and was re cleared for the ILS Approach. Several minutes later the VFR aircraft identified itself as Aircraft Y. Company traffic; Aircraft Z had reported to me that Aircraft Y following him out of KOA. I had reached out to Aircraft Y but they were not on frequency. When Aircraft Y did come up on frequency I asked if they had had the Aircraft X in sight and he responded that he had. I asked as professionally and courteously as I know how that he please contact center for VFR advisories in the future to avoid this situation in the future. This airport is way past being serviced by enroute radar approach control. There absolutely needs to be a terminal radar and Class C services to that airport.
HCF TRACON Controller had to vector an air carrier off of the ILS Approach to avoid unidentified conflicting VFR traffic.