Small Aircraft; Low Wing; 1 Eng; Retractable Gear
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 3.5
Communication Breakdown; Distraction; Situational Awareness; Workload
ATC Issue All Types; Conflict NMAC; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Provided Assistance; Flight Crew Executed Go Around / Missed Approach; Flight Crew Took Evasive Action; Flight Crew Returned To Departure Airport
Airport; Aircraft; Procedure; Human Factors
I was relieved of Local Control and it was busy. During the overlap; the relieving controller had a go around with Aircraft X on Runway 17 and told them to extend upwind 3 miles. Aircraft Y was in the pattern for the parallel Runway 16 and was turning crosswind. Local Control told Aircraft Y to make a wide right 270 to enter the downwind. Majority of our attention was north of the field given that there were so many inbounds being sequenced. I looked on the radar and out the window and saw that Aircraft Y and Aircraft X were getting close; even though they shouldn't have been. I told Local Control about it and before he could key up; Aircraft X [reported] a NMAC and requested to leave the airspace.I believe Aircraft Y misunderstood what was being requested of him because it looked more like he tried to fly heading 270 instead of doing a 270 maneuver.
FTW Tower controller reported a near mid air collision in the pattern when one pilot misunderstood the clearance.