Tower Local Controller reported a departing Air Carrier encountered a NMAC with a VFR survey mission aircraft. The Controller and their trainee failed to issue traffic information to either aircraft and handed them off to adjacent airspace frequencies.
Synopsis
Tower Local Controller reported a departing Air Carrier encountered a NMAC with a VFR survey mission aircraft. The Controller and their trainee failed to issue traffic information to either aircraft and handed them off to adjacent airspace frequencies.
Narrative
Prior to the event; this session had been very taxing on both myself as a trainer and the trainee. For my experience level there wasn't much complexity if I had been working the traffic on my own. However; for the trainee it was which made it difficult for both of us. Earlier in the session; we had two VFR's in the pattern. I had to do a lot of prompting/teaching/training and it was a lot for both of us. After this; I noticed signs that the trainee was flustered. Stumbling over his words; making multiple typing errors etc. and I should have ended the training. If I had this would not have taken place. However; he continued training and continued struggling. Prior to the event the trainee made a decision that was not the most efficient/effective decision that I was explaining to him. During this time Aircraft X was on departure roll. The Aircraft Y had been maneuvering approximately 4 miles southeast ZZZ and never came further west than midfield. So they weren't a factor initially. So I looked away to jot down some notes. I heard and looked up when the Aircraft Y said their next operation would be 1 mile north ZZZ1. At that time they were still no factor for Aircraft X. I assumed they would go directly southbound and thus not be a factor for Aircraft X so I again looked away to write. I heard the trainee switch Aircraft X to ZZZ [Approach]; then switch the Aircraft Y to ZZZ1 Tower. I was made aware of the developing situation by the Controller in Charge (CIC) after both aircraft had already been switched. When I looked up Aircraft X was about 1.5 miles northwest of the Aircraft Y who was flying due west. Aircraft X began to climb and at the point that he crossed directly overhead the Aircraft Y he was approximately 800 ft. above him. However; both aircraft had already been switched. The trainee said he called traffic but after listening to the tapes afterwards he hadn't. ZZZ called and reported that the Aircraft X reported a near mid-air. I immediately ended training at that point. I continued to work until being relieved. In our debrief; the trainee and I reviewed the tapes. We also reviewed the radar display replay with the Supervisor. There were several missed opportunities that would have/should have prompted the trainee to issue traffic. This particular trainee has nearly 400 hours and is currently on an extension. He was given nearly double the normal amount of hours allotted to local trainees because of Covid. The consensus of the training team is that he is close but he has to show consistency. I again feel bad because I wish I would have ended the session sooner and this would not have happened. I should have recognized we both were taxed from earlier in the session and possibly that's why we both missed it. I also feel like the Swiss cheese model; we were failed by the CIC who didn't see it until after both aircraft were already switched. I'm not really sure what to recommend. I will as a trainer going forward try and do better at realizing when either my trainee or myself is overwhelmed and either take over or end training. I also felt as if the Tower team failed. When I work CIC I take a more active hands on approach in assisting trainer/trainees because I know how taxing training can be and how easily things can be missed. Had the CIC recognized this sooner as well we could have resolved the issue.
Second reporter narrative
Aircraft X departed Runway XXR and was given an altitude restriction of 4000 ft. in which said aircraft read back then begun departure procedures. Aircraft Y was performing east to west survey lines just east of ZZZ1 airspace restricted at 2700 ft. Aircraft Y was pointed out to ZZZ Area sector which was combined with Area 1 sector and also a verbal point out was approved by ZZZ1 Tower as well. Aircraft X was climbing via the ZZZZZ.3 departure and instructed to contact ZZZ Departure. Aircraft Y informed me that they would like to perform more survey work one mile north of ZZZ1 Airport and would like to contact ZZZ1 Tower. I then informed Aircraft Y radar services was terminated and to contact ZZZ1 Tower. Aircraft X had to performed a rapid climb out of 2500 ft. to climb above Aircraft Y which was at 2600 ft. Aircraft X climbed 800 ft. to 900 ft. above Aircraft Y. This happened because traffic was not exchanged between both aircraft and preventative measures was not set in place. First and foremost traffic should have been exchanged between both aircraft and if preventative measures was not set in place then it should have been a SAFETY ALERT. Aircraft Y should have been issued the traffic and instructed to descend into ZZZ1 airspace once all conflicts was resolved then instructed to contact ZZZ1 Tower. Aircraft X should have been informed of said traffic and instructed that said traffic was descending if preventative measures was in place. Above all a safety alert should have been issued before instructing either aircraft to contact the Area 1 sector or ZZZ1 Tower.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.