Narrative:

I was instructing a student. We were returning from pattern work and other practice in the vicinity of a nearby airport. My student selected the AWOS frequency for our landing airport and after obtaining the winds of 220 at 6 he selected the wrong runway. We then discussed which runway to use; 34 or 16. I failed to notice that he did not select the CTAF frequency for the airport. With the frequency for the other airports CTAF in COM1 he began announcing our location in the pattern.the student has a very verbose communication style and he was talking about the approach path as we approached the downwind leg for runway 16. I reminded him he didn't have much time to get his checklist done and he began to run through his checklist after we turned downwind. The turn to base leg at our landing airport is somewhat 'tight' as there is a residential area that pilots try to avoid flying over. As we approached the residences I directed the student to turn base. My attention was on his execution of the pattern and I hadn't noticed the lack of radio traffic. I also didn't emphasize scanning the area like I should have; as it was dusk and I assumed the area was quiet.while on base; I saw a high-wing aircraft in a turn headed in the opposite direction; slightly to our left (north) and approximately 75 ft above us. It quickly passed us and my student never saw it; nor did we make any evasive maneuvers. Glancing at our radio I noticed that the CTAF was not selected; and quickly selected the correct frequency as my student focused on his final approach. Once on frequency I heard the other aircraft making position reports and continuing to fly the pattern for runway 34.after landing I announced on the CTAF that we were departing the runway. The other aircraft continued to perform several touch-and-goes on runway 34 before departing the area. Judging from the tone of voice from the other aircraft's pilot; they may have never seen us or realized the loss of separation that occurred. They sounded very 'routine' on the radio. After I announced that we were off the runway they did not respond to us at all.as to the cause of the problem; it started with missing that the student failed to select the CTAF frequency before making position reports in the pattern. It is probable that the discussion of 'the correct runway' led to this distraction. Contributing to the incident situation was inadequate lookout on my part; focusing on the student's poor performance in the pattern. Another factor was the other aircraft using the 'wrong' runway; accepting a tailwind; so they were in an 'unexpected' location. Approaching darkness led to decreased visibility; and also an 'expectation' that there would not be other aircraft in the pattern.

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Original NASA ASRS Text

Title: An instructor pilot and his Private pilot student suffered an NMAC entering the pattern. A significant contributing factor was the student's failure to retune and transmit position and intention reports on the correct CTAF frequency.

Narrative: I was instructing a student. We were returning from pattern work and other practice in the vicinity of a nearby airport. My student selected the AWOS frequency for our landing airport and after obtaining the winds of 220 at 6 he selected the wrong runway. We then discussed which runway to use; 34 or 16. I failed to notice that he did not select the CTAF frequency for the airport. With the frequency for the other airports CTAF in COM1 he began announcing our location in the pattern.The student has a very verbose communication style and he was talking about the approach path as we approached the downwind leg for Runway 16. I reminded him he didn't have much time to get his checklist done and he began to run through his checklist after we turned downwind. The turn to base leg at our landing airport is somewhat 'tight' as there is a residential area that pilots try to avoid flying over. As we approached the residences I directed the student to turn base. My attention was on his execution of the pattern and I hadn't noticed the lack of radio traffic. I also didn't emphasize scanning the area like I should have; as it was dusk and I assumed the area was quiet.While on base; I saw a high-wing aircraft in a turn headed in the opposite direction; slightly to our left (north) and approximately 75 FT above us. It quickly passed us and my student never saw it; nor did we make any evasive maneuvers. Glancing at our radio I noticed that the CTAF was not selected; and quickly selected the correct frequency as my student focused on his final approach. Once on frequency I heard the other aircraft making position reports and continuing to fly the pattern for Runway 34.After landing I announced on the CTAF that we were departing the runway. The other aircraft continued to perform several touch-and-goes on Runway 34 before departing the area. Judging from the tone of voice from the other aircraft's pilot; they may have never seen us or realized the loss of separation that occurred. They sounded very 'routine' on the radio. After I announced that we were off the runway they did not respond to us at all.As to the cause of the problem; it started with missing that the student failed to select the CTAF frequency before making position reports in the pattern. It is probable that the discussion of 'the correct runway' led to this distraction. Contributing to the incident situation was inadequate lookout on my part; focusing on the student's poor performance in the pattern. Another factor was the other aircraft using the 'wrong' runway; accepting a tailwind; so they were in an 'unexpected' location. Approaching darkness led to decreased visibility; and also an 'expectation' that there would not be other aircraft in the pattern.

Data retrieved from NASA's ASRS site as of April 2012 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.