Date: 201310
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 50
Light: Daylight
Aircraft: Aeronca Champion
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Final Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Second aircraft: SR20
Reporter organization: Personal
Reporter function: Single Pilot; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Distraction; Situational Awareness; Communication Breakdown; Confusion
Anomaly: ATC Issue All Types; Conflict NMAC
Detector: Person Flight Crew
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: During right hand closed traffic on Runway X; the Tower cleared me for the 'option'; and after that; enter a left downwind for [the crossing runway]; Runway Y. [When I was] established on a left downwind for Runway Y; the Tower called out traffic on final for Runway Y; and that I was 'Number 2'. I reported the traffic in sight. The traffic was using a [locally recognized flight school] call sign. I was then 'cleared for the option Runway Y; Number 2'. I was then told to make right traffic for Runway Y after that. I acknowledged. After a normal touch and go behind the traffic; I still had them ahead of me in the upwind in sight. The Tower then again told me to make right traffic. I acknowledged in the affirmative. The Tower then immediately asked me to make left traffic Y. I acknowledged again. At 400 feet AGL; I turned a left crosswind; and the traffic was still in an upwind. On left downwind; the Tower cleared me for a touch and go Runway Y. I acknowledged. The traffic I had been following was on the right hand crosswind for Runway Y; and I had them in sight. I turned a left base for Runway Y; and the low sun was bright. I then started a turn to final; a 2nd [flight school aircraft] emerged from under the nose of my aircraft. I initiated a go around; and [still] had the first traffic in sight on the right hand downwind. As I initiated my go around; the Tower instructed the first [flight school aircraft]; still on downwind; to go around. The Tower Controller had the two call signs confused. I turned a left crosswind; then left downwind; and then exited the area to the north. The Tower Controller never issued a traffic report for the [second aircraft]. The Tower Controller never told me that I was #2 for the field. The Tower was confused between the two aircraft and their similar call signs. The bright sun and the lower position of the second aircraft impeded my vision on left base for Runway Y. Although I verified final was clear before turning onto final; the aircraft's was position was not possible to see.




Synopsis: The pilot of an Aeronca Champ was performing pattern work at a Tower controlled airport with a local flight school aircraft. The Tower Controller became confused by the flight school call signs and did not recognize that another aircraft was a conflict for the Champ traffic. The Champ pilot did not initially see the other aircraft due to the sun angle; resulting in a NMAC condition.