Date: 202108
Local time of day: 1201-1800
Location: ZZZZ.ARTCC, FO
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Final Approach
Airspace: Class B ZZZZ
ATC / advisory: CTAF ZZZZ1
Second aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Reporter organization: Personal
Reporter function: Captain; Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Human factors: Communication Breakdown; Confusion; Workload; Distraction; Situational Awareness; Time Pressure
Anomaly: ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Environment - Non Weather Related; Human Factors; Airspace Structure
Primary problem: Human Factors

Narrative: This is the second time I have landed at ZZZZ1 (the first was a normal IFR landing at dusk 2 years earlier). ZZZZ1 is a high use uncontrolled training airport located under ZZZZ's Class B airspace. It proved to be a very busy afternoon with 4 to 6 aircraft simultaneously in the pattern. Some pilots had very limited English proficiency. The ATIS listed in ForeFlight for ZZZZ1 is actually for ZZZZ so the Runway information is misleading. The lack of clear communications and the traffic density resulted in my experiencing Task Saturation for the first time since I completed my training 20 years earlier.Issue 1 - Unexpected runway change. Based on my communications with ATC I was expecting to land on Runway XX from my IFR approach and did not have warning that Runway XY was the active runway until after being instructed by ZZZZ to change to the ZZZZ1 Unicom. After listening to the ZZZZ1 Unicom I broke off my approach to Runway XX because I found the conflicting runway was in use and sought to understand what the traffic was doingIssue 2 - Confusion TCAS/sight/radio reports. As I approached the airport; the aircraft I saw in the air; corresponded with the aircraft I saw on the TCAS screen. The self-announcement pattern positions from the aircraft appeared to correspond with what I saw in the air and on TCAS. What I did not realize was the aircraft I saw were not the ones reporting the positions I heard. There were likely others in the same relative position at the opposite end of the field at the same time. I consequently unintentionally set myself up for Runway XZ thinking it was Runway XY. I did a 45-degree entry into what I thought was the left downwind leg for Runway XY and a heard conflicting mid field downwind traffic report which I could not locate and decided to exit the pattern and reenter. Another pilot informed me I was actually on the upwind side for Runway XY and I subsequently set myself up in sequence for entry into the pattern for Runway XY.  As I was in the downwind someone used 20 seconds on the Unicom asking for a weather radar for an area 20 miles report north of the airport. On downwind I slowed down for the aircraft in front. The only part of their call sign I could understand was Aircraft Y. Aircraft Y called base. I called base. Aircraft Y called final. I extended my downwind a bit and later called final. I lost sight of Aircraft Y and as I was trying to reestablish their location; I lowered the nose to see. Aircraft Y eventually came into my view as I was abeam him; but I could not reduce speed further to get behind him. He was low and to the right of the final approach course. In hindsight my best guess is he was doing 65 kts. or less (my minimum normal approach speed is 80 kts.) When I had become aware we were converging I advised him and he said 'sir that's illegal ??? theres off the words two cows on the left on final' [Verbatim]. I was trying to make sense of what he had just said and was preparing to go around but then I heard him say 'Going around for Runway XY' at which point I thought the safest thing to do at that point was continue with my landing on Runway XY. There was no injuries or damage to either aircraft.As I was focusing on situational awareness another pilot consumed 20 seconds on the Unicom asking someone on the Base radio to check the weather radar well north of the Airport. Having the pattern frequency used for other purpose reduced everyone's opportunity for situational awareness. ZZZZ ATC was very insistent I understood they were holding the airspace open for me and twice read me an 800 number to call on the ground. I felt pressured to cancel IFR while in the air. After landing I later saw a sign in the Pilot Dispatch area saying 'keep the Unicom Free' and advising the use of XXX.XXX for Weather and Airport information. However; the frequency is not published in [our database] and when a local CFI and I tried it a few days later we found it was inoperative.The pilot in Aircraft Y I conflicted with was often impossible to understand; even though he had made several radio calls; I could never establish what his call sign was. Variations in US/Country X procedures. I entered the pattern per US VFR entry rules; I was not aware the [country] rules do not allow for two of the common US VFR entry methods. Given its location relative to the ZZZZ Class B airspace the remaining VFR entry options are very limitedI found having coverage terminated by ATC with limited prior airport information severely impacted my situational awareness; resulting in the beginnings of task saturation. Use of the Unicom for non-essential communications reduced opportunities for everyone to provide position reports. I lost a sense of where Aircraft Y was; and when Aircraft Y came into my view I was already abeam him. Normally I would have immediately gone around but I was trying to understand what he was saying.I have since reviewed the [country] VFR pattern entry rules with a local CFI and done several VFR pattern entries with him at ZZZZ1. I have booked time with my regular CFI to reevaluate and refresh my VFR skills and go over the incident with him. In future I will assume my runway can be reassigned to anything at anytime after arrival and will study every runway before arrival and map out the situational awareness should I be required to change. I will put the Common traffic frequency in Radio two and monitor ten miles out (well before instructed by ATC) to determine what runaway is being used rather than wait until the controller says to switch.A dedicated ZZZZ1 ATIS (rather than using ZZZZ's) that included announcing the active runway in use would have reduced confusion and would do a lot to help be prepared for the current traffic pattern. A dedicated ZZZZ1 ATIS with weather remarks appended (rather than using the common Unicom frequency) would have reduced the need for other pilots to ask someone to check the weather and increased the available time for all pilots to provide position reports. Audit students' ability to clearly communicate in English when in the pattern and especially under stress.




Synopsis: Single Engine Pilot reported a NMAC while in the traffic pattern at a non towered airport on foreign soil; and cited as contributing lack of clear communications; traffic density; an unexpected runway change; and gaps in the reporter's knowledge of the foreign country's flight rules.