Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 4
Distraction; Situational Awareness
ATC Issue All Types; Conflict NMAC
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Human Factors
I was working two radar sectors combined with a trainee and trainer as my coordinator. The traffic volume was high with the normal arrivals; departures; overflights; and practice instrument approaches. The complexity was high due to a 10 minute notice of a flight check aircraft that needed to check an opposite direction approach. Once the flight check aircraft started his opposite direction approach I started briefing the relieving controller in training for a sector split. As the flight check aircraft had just finished with the opposite direction approach and continuing to brief the relieving controller for the split; I radar identified the flight check aircraft and turned him on course for the next approach. As all that was happening; I was descending and vectoring Aircraft X for the ILS approach to a different airport. Aircraft X was the second aircraft in the sequence of three for the ILS approach. As Aircraft X crossed 2 miles north of a satellite airport; Aircraft Y was departing VFR north bound climbing to 3;000 ft. without any communication with me. I called the traffic as soon as I saw the issue and Aircraft Y reported that he was maneuvering to avoid collision. A few seconds later Aircraft Y called VFR looking to pick up his IFR flight plan. Also the weather at each facility within the airspace was overcast or broken around 2;200 ft.
TRACON Controller reported they were distracted by splitting a combined sector and a flight check aircraft and did not notice two aircraft in confliction which resulted in a NMAC.