Small Aircraft
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 1.5
Workload; Situational Awareness; Time Pressure
ATC Issue All Types; Conflict NMAC
Flight Crew Took Evasive Action
Human Factors; Airspace Structure; Procedure
Working Radar; Handoff; and another sector combined. Aircraft X; contacted me requesting VFR advisories. Aircraft X was radar identified eastbound at 1;400 feet. Aircraft Y departed on the North Shore Departure; VFR; was radar identified. I observed the conflict and issued traffic to both aircraft. Both aircraft responded that they were searching for traffic; neither reported traffic in sight. When Aircraft Y reached the boundary of the Class C; he requested termination of radar services and frequency change. I issued traffic to Aircraft Y once more before terminating radar services. After the traffic passed; Aircraft Y transmitted on frequency (I believe this was directed at Aircraft X) that they didn't appreciate the maneuver performed by Aircraft X as they passed each other.I was working multiple frequencies and did not have time to have a conversation over frequency about exactly what had happened. After Aircraft X landed he reached out to me on frequency to indicate his concern about the event. He informed me that he was forced to perform an 'emergency climb' to avoid Aircraft Y and stated that he 'almost hit him'. At the time prior to the event; both aircraft were outside of the Class C airspace. During each aircraft's avoidance maneuvers; one or both of the aircraft may have penetrated the Class C shelf.No recommended airspace or procedure changes. Event was a combination of frequency congestion; traffic complexity and volume; and possibly inability of pilots to see and avoid other aircraft.
A11 TRACON Controller reported an aircraft had an NMAC with another aircraft the Controller had just terminated radar with.