Date: 202011
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Champion Citabria 7ECA
Operator: FBO
Operating under: Part 91
Flight plan: None
Mission: Training
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Second aircraft: Champion Citabria 7ECA
Reporter organization: FBO
Reporter function: Pilot Not Flying; Instructor
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Commercial; Flight Crew Multiengine; Flight Crew Instrument
Human factors: Other / Unknown; Training / Qualification
Second reporter function: Pilot Flying
Anomaly: Conflict NMAC; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew; Person Observer
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: I am a flight instructor I was on the ground observing the traffic pattern. I had just sent my student on his first solo flight. There were three Citabrias in the pattern; all same company. My solo student was Aircraft X. Aircraft Z was on ½ mile final. Aircraft Y was on an extended downwind. My student; Aircraft X; was abeam midfield in the downwind. All traffic was in a left pattern. Tower called and told my student 'traffic to follow ahead in the downwind'. My student replied with 'traffic in sight'. My student had mistaken Aircraft Z on final as the traffic he was following; instead and of seeing and following Aircraft Y in the downwind. Tower proceeded to clear my student 'follow that traffic; clear to land Runway XX'. Because my student was following the wrong aircraft; he turned base (about a half mile) in front of Aircraft Y and cut him off. Aircraft Y was on a 1 mile final at the time. Aircraft Y saw the error and made appropriate maneuvers. Tower noticed when Aircraft X had turned final in front of Aircraft Y and proceeded to tell both aircraft to go around. No further events took place. The pilot in Aircraft X did not see or follow the correct traffic and turned base accordingly. He unintentionally deviated from the ATC clearance. The plot of Aircraft Y noticed and took evasive actions as necessary. I was on the ground and all distances are highly estimated.


Second narrative: I was given traffic information by ATC while on downwind leg of pattern; a Aircraft X in the pattern ahead and to my left. I saw an aircraft matching ATC description on short final approach and responded that I had the traffic in sight. ATC gave landing clearance with instructions to follow that aircraft; so when I had sufficient distance behind I began my turn to the base leg of the pattern. Upon turning I spotted another aircraft ahead and to my right at about 500 feet clearance on final approach. I took a hard left turn to evade and was told by ATC to go around and that the aircraft I flew in front of was the traffic I was originally advised of and that I had cut them off. I continued in the traffic pattern and landed without further incident.


Synopsis: A Flight Instructor observing from the ground and their student reported the student turned base leg and followed the wrong aircraft causing a subsequent aircraft to take evasive action.