Small Aircraft; High Wing; 1 Eng; Retractable Gear
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (mon) 43
Situational Awareness; Distraction; Communication Breakdown; Training / Qualification; Workload
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Separated Traffic; Air Traffic Control Provided Assistance
Human Factors; Procedure
I was training a developmental whom I have never trained before in the radar room. Seeing that I have never trained them; I was unaware of their ability and technique. Aircraft X departed an airport in the southern portion of our airspace; flying northbound. The developmental put the aircraft on a 340 heading to keep the aircraft clear of the departure area. Aircraft Y departed [a nearby airport] VFR to perform sky dive operations above the Bravo airspace. As Aircraft X neared Aircraft Y; Aircraft Y was in a westbound heading; climbing away from Aircraft X.Letting the situation go as far as I saw it could without stepping in; I took over the frequency and advised Aircraft Y to continue a VFR climb to the West and called the traffic (at this time they were about 2 NM separated and divergence was also maintained). I received no read back from Aircraft Y and called to them again telling to them fly westbound. After no response again; I called the traffic to Aircraft X. At this time; Aircraft Y had continued their counterclockwise turn and ended up closing in on Aircraft X. Aircraft X called the traffic and I advised him to maintain visual separation.Satellite should have been split out during this session. There was an airshow just north of our airspace which added greatly to the complexity; especially to a developmental who has had just a couple of hours of satellite training. Also at this trainee's stage in training; satellite should only be trained stand alone. Parachute operations should not be occurring in Bravo airspace; especially mere miles into the departure area of a level 9 airport.I shouldn't have been training the individual. I had been out of work on [personal leave]. I came in expecting to maintain currency and instead was not only given a 9 hour turnaround; but was instructed to train a development whom I have had no experience with.The Supervisor/CIC had been on position for approximately 4 hours at the time of the event due to lack of CIC's in the facility. Had they had a non-fatigued mind; they would have had the opportunity to aid in preventing the event.Due to lack of CIC's in the facility; I have a problem maintaining currency. The majority of the time I am in the operations I am sitting 'in charge;' and due to this have lost proficiency.
TRACON Controller reports of a loss of separation between two aircraft. Controller was training a Developmental that he was unfamiliar with and let the situation go too far. Instructor took over but aircraft did not respond timely.