Narrative:

I was training a developmental that had 140 plus hours on local control. Runway 23 was active and aircraft X was in the right downwind. Aircraft Y was on the right base to runway 23. Aircraft X was instructed to make a left 360 when they were midfield. As they were rolling out of the 360 I pointed the aircraft out to the developmental. She instructed them to make another tight left 360 and they acknowledged. We did not tell aircraft Y about aircraft X in a 360 abeam the numbers. We did tell aircraft X about aircraft Y and they would be number 3 to follow. I told the trainee traffic for one is traffic for another but we never called it on frequency.we had an aircraft on short final so I scanned gear and the runway. A helicopter was operating on the east side of the airspace. They called up to tell us they were tracking RT3 northbound and they were going to be hovering on about a 3 mile final for RWY23. As I scanned back to the northwest; aircraft Y keyed up and said they had traffic directly ahead and inquired what they were doing. They also said they took evasive maneuvers to avoid. At this point I keyed up let aircraft Y know the traffic was now behind them and they were cleared to land. I told aircraft X they were #2 and cleared to land. I saw out the window what was happening but the helicopter was still talking blocking the frequency. Aircraft X flew at least another mile in the downwind from when being instructed to make a 360 and when they started it. Aircraft X complied with the first 360 appropriately.the atm and two people for an ecv audit were upstairs. Additionally; the controller in charge/ground control/FD positions were combined and there was a position relief briefing in progress. A90 had called twice over the shout line to coordinate an arrival to RWY29 at the same time. Change my scanning techniques. I saw aircraft X abeam the numbers and they went to the rwy. The helicopter called so I looked and scanned their flight path before going back to aircrafts X and Y. I could've reached out on guard to see if either aircraft were monitoring.

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Original NASA ASRS Text

Title: BED Tower controllers reported an aircraft was supposed to make a 360 on downwind; but did not and caused a conflict with a helicopter.

Narrative: I was training a developmental that had 140 plus hours on local control. RWY 23 was active and Aircraft X was in the right downwind. Aircraft Y was on the right base to RWY 23. Aircraft X was instructed to make a left 360 when they were midfield. As they were rolling out of the 360 I pointed the aircraft out to the developmental. She instructed them to make another tight left 360 and they acknowledged. We did not tell Aircraft Y about Aircraft X in a 360 abeam the numbers. We did tell Aircraft X about Aircraft Y and they would be number 3 to follow. I told the trainee traffic for one is traffic for another but we never called it on frequency.We had an aircraft on short final so I scanned gear and the RWY. A helicopter was operating on the east side of the airspace. They called up to tell us they were tracking RT3 northbound and they were going to be hovering on about a 3 mile final for RWY23. As I scanned back to the northwest; Aircraft Y keyed up and said they had traffic directly ahead and inquired what they were doing. They also said they took evasive maneuvers to avoid. At this point I keyed up let Aircraft Y know the traffic was now behind them and they were cleared to land. I told Aircraft X they were #2 and cleared to land. I saw out the window what was happening but the helicopter was still talking blocking the frequency. Aircraft X flew at least another mile in the downwind from when being instructed to make a 360 and when they started it. Aircraft X complied with the first 360 appropriately.The ATM and two people for an ECV audit were upstairs. Additionally; the CIC/GC/FD positions were combined and there was a position relief briefing in progress. A90 had called twice over the shout line to coordinate an arrival to RWY29 at the same time. Change my scanning techniques. I saw Aircraft X abeam the numbers and they went to the rwy. The helicopter called so I looked and scanned their flight path before going back to Aircrafts X and Y. I could've reached out on guard to see if either aircraft were monitoring.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.