Large Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2.5
Workload
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Executed Go Around / Missed Approach
Staffing; Procedure; Human Factors
I was working Sectors 2; 4; and 5 combined; with no D side. The Supervisor had decided to combine the sectors a half hour earlier than normal. The traffic was a little busier than normal; but with the added sector; it was pretty busy. I was working a sequence of three IFR aircraft into KOA; Aircraft Y; Aircraft Z; and Aircraft X. I was also talking to other planes at the time; and I failed to notice the time. As I worked to get the required spacing for the sequence into KOA; Kona Tower called and said that they were closing (this means KOA becomes one in; one out.) Because of this; I had to put the last two aircraft in my sequence into holding. The first and second aircraft ended up canceling IFR; so I cleared Aircraft X for an ILS approach. I had a VFR target on radar that I pointed out to Aircraft X prior to termination. Aircraft X just said; 'Roger; looking.' I terminated Aircraft X and switched him to advisory frequency. A few minutes later; I observed Aircraft X having a conflict alert with the 1200 squawk. Their targets were overlapping and I saw them at 100 feet apart; with Aircraft X on top. I then saw Aircraft X climb out of 1;500 to 2;800 feet (I think; I can't remember the exact altitude.) Aircraft X overflew the field and did what looked like a go around. They never contacted me. At this point; I gave a relief briefing to the next controller. During the two minute overlap; I heard Aircraft X report down on the ground at Kona. They did not report a TCAS RA. By this time; I had been on position for 2 hrs 48 minutes without being offered a break.I should have paid more attention to the time and known that KOA Tower was going to close. This was a dangerous situation. The sectors shouldn't have been combined earlier than normal; this led to increased traffic which decreased my awareness. I shouldn't have been on position for so long (that might have helped my awareness of time.) I had been working for so long with busy traffic that I felt myself having to work harder than normal to focus on the task at hand. I should have held on to Aircraft X longer and tried to keep pointing out traffic. Since Aircraft X was on an ILS approach; he should have called on the missed approach.
HCF Approach Controller describes situation where he has an IFR aircraft going into a non-controlled airport with other traffic known to him that are also going to the airport. Controller issued one traffic; IFR executed missed approach due to traffic close proximity resulting in a NMAC.