Narrative:

While in the traffic pattern at chandler municipal airport; under the direction of chandler tower; I was accomplishing touch and go landings. Several landings were made on runway 22L with left traffic being used and at least one on runway 22R with right traffic being used. On one of the touch and goes while on the upwind leg after takeoff; I had noticed that the tower frequency had been switched to ground control. On this specific aircraft there is a switch on the yoke that transfers the active and standby frequency. My guess is that when reading the landing clearance back to tower; the frequency switch button was depressed instead of the push to talk button also located on the yoke. Climbing through approximately 500 feet AGL; I noticed the frequency was not correct and immediately checked in with chandler tower. At that time I was not aware of any traffic conflict nor was advised of any traffic conflict. A full stop was requested and the traffic pattern was flown. On final approach; a landing clearance had not yet been given by tower so a go around was initiated. Another traffic pattern was flown and a full stop landing was made. The taxi in and shutdown was uneventful. I did not know of any traffic conflict until [later] when I was informed of a FAA near mid air collision system report being filed. This is the only anomaly that occurred during the flight and is why I am assuming this is when the near miss event occurred.

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Original NASA ASRS Text

Title: PA-28 pilot reported he was advised after the fact that he was involved in an NMAC in the pattern at CHD airport.

Narrative: While in the traffic pattern at Chandler Municipal Airport; under the direction of Chandler Tower; I was accomplishing touch and go landings. Several landings were made on runway 22L with left traffic being used and at least one on runway 22R with right traffic being used. On one of the touch and goes while on the upwind leg after takeoff; I had noticed that the tower frequency had been switched to ground control. On this specific aircraft there is a switch on the yoke that transfers the active and standby frequency. My guess is that when reading the landing clearance back to tower; the frequency switch button was depressed instead of the push to talk button also located on the yoke. Climbing through approximately 500 feet AGL; I noticed the frequency was not correct and immediately checked in with Chandler Tower. At that time I was not aware of any traffic conflict nor was advised of any traffic conflict. A full stop was requested and the traffic pattern was flown. On final approach; a landing clearance had not yet been given by tower so a go around was initiated. Another traffic pattern was flown and a full stop landing was made. The taxi in and shutdown was uneventful. I did not know of any traffic conflict until [later] when I was informed of a FAA Near Mid Air Collision System report being filed. This is the only anomaly that occurred during the flight and is why I am assuming this is when the near miss event occurred.

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.