Narrative:

I was working the local control position at the time of the event. Aircraft Y had just departed for left closed traffic. Aircraft X was on final. We were advertising 1;200 ft. Ceilings at the time. Aircraft Y was midfield when he advised that he wanted a stop and go. I told him that if he wanted a touch and go that he could be number one. Aircraft Y didn't respond so I told him to extend his downwind and that I would call traffic for him to follow as he got closer. He didn't respond again so I repeated for him to extend his downwind to which he complied. As I looked up at the radar after scanning the runway; I noticed that aircraft Y was tracking close to the final with aircraft X closing in. I instructed him to make a right 360 degree turn to get him more comfortably out of the way for the inbound aircraft X. At this point I saw aircraft Y start his turn and I had tower apply visual separation between aircraft Y and aircraft X. Aircraft X asked if there was traffic ahead of him and I told him it was ahead and to his left; 1;000 ft. Northbound. Aircraft X responded; 'roger; we're getting a TCAS RA (resolution advisory) and we're climbing.' I said roger; then came back with fly runway heading and maintain 3;000 ft. To which aircraft X complied. Aircraft X was vectored around by approach for a safe landing; and aircraft Y did a lap in the local traffic pattern and landed safely as well. Make sure to let everyone know about everyone in a more timely manner; and insure that with weather moving in that ATC instructions are more promptly followed by aircraft.

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Original NASA ASRS Text

Title: PWM Tower Controller and Air Carrier Captain reported an aircraft in the VFR pattern not complying with ATC instructions and conflicting with traffic; resulting in a TCAS RA.

Narrative: I was working the Local Control position at the time of the event. Aircraft Y had just departed for left closed traffic. Aircraft X was on final. We were advertising 1;200 ft. ceilings at the time. Aircraft Y was midfield when he advised that he wanted a stop and go. I told him that if he wanted a touch and go that he could be number one. Aircraft Y didn't respond so I told him to extend his downwind and that I would call traffic for him to follow as he got closer. He didn't respond again so I repeated for him to extend his downwind to which he complied. As I looked up at the radar after scanning the runway; I noticed that Aircraft Y was tracking close to the final with Aircraft X closing in. I instructed him to make a right 360 degree turn to get him more comfortably out of the way for the inbound Aircraft X. At this point I saw Aircraft Y start his turn and I had Tower apply visual separation between Aircraft Y and Aircraft X. Aircraft X asked if there was traffic ahead of him and I told him it was ahead and to his left; 1;000 ft. northbound. Aircraft X responded; 'Roger; we're getting a TCAS RA (Resolution Advisory) and we're climbing.' I said roger; then came back with fly runway heading and maintain 3;000 ft. to which Aircraft X complied. Aircraft X was vectored around by Approach for a safe landing; and Aircraft Y did a lap in the local traffic pattern and landed safely as well. Make sure to let everyone know about everyone in a more timely manner; and insure that with weather moving in that ATC instructions are more promptly followed by aircraft.

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.