Narrative:

Aircraft X entered the left traffic pattern. Two [small transports] were in the pattern. Aircraft X announced downwind airspeed of 80 knots. Twice during multiple approaches aircraft Y initiated right traffic patterns. Aircraft X did announce 'standard pattern to left;' with no response. Once aircraft Z was on a right base almost at the same time aircraft X was about to make a left base. AC-90-66B clearly states left hand traffic pattern is standard. This is the second time this conflict has happened. I understand [these aircraft] have a training requirement for right patterns. Training requirements do not trump fars at non-government airports. A NASA ASR was submitted about a year ago for the same conflict. A nearby airport has two runways that require right traffic patterns. The event noted resulted in head-on situations resulting from non-standard pattern and standard left pattern operations.

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Original NASA ASRS Text

Title: Small aircraft pilot at a non towered airport reported two other aircraft were making non standard right traffic patterns and not communicating on the appropriate frequency.

Narrative: Aircraft X entered the left traffic pattern. Two [Small Transports] were in the pattern. Aircraft X announced downwind airspeed of 80 Knots. Twice during multiple approaches Aircraft Y initiated right traffic patterns. Aircraft X did announce 'Standard Pattern to Left;' with no response. Once Aircraft Z was on a right base almost at the same time Aircraft X was about to make a left base. AC-90-66B clearly states left hand traffic pattern is standard. This is the second time this conflict has happened. I understand [these aircraft] have a training requirement for right patterns. Training requirements do not trump FARs at non-government airports. A NASA ASR was submitted about a year ago for the same conflict. A nearby airport has two runways that require right traffic patterns. The event noted resulted in head-on situations resulting from non-standard pattern and standard left pattern operations.

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.