Narrative:

I radioed turning downwind for 34. As I turned from x-wind to downwind I did not see the other aircraft on the x-wind but was told by the instructor that was behind him that he 'turned behind you a little closer than he should have'. Mid downwind I looked behind me to see how busy it was so I could judge my base turn to keep a good flow of the traffic in the pattern. I saw an small aircraft very close to me in the downwind. I would have guessed he was 500-1000' behind me. I thought the small aircraft was just being a little funny and playing games with me. He had (I believe) to have seen me in the downwind because he's directly behind me at an altitude not more than 10' from mine. So figuring he saw me I proceeded to fly my downwind. I did hear him call a left turn for an east departure. I called a base turn at the standard 45 degree off my shoulder from the touchdown point in the downwind. I and my student looked for traffic and proceeded to turn the base leg. When we rolled out of our bank there was the small aircraft 200-300' just a little bit higher than us (100') away from us. I banked semi steeply to the right and added some more pitch to the descent attitude.

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Original NASA ASRS Text

Title: PLT OF SMA HAD NMAC WITH SMA IN UNCONTROLLED VFR TRAFFIC PATTERN AT AUXILIARY ARPT.

Narrative: I RADIOED TURNING DOWNWIND FOR 34. AS I TURNED FROM X-WIND TO DOWNWIND I DID NOT SEE THE OTHER ACFT ON THE X-WIND BUT WAS TOLD BY THE INSTRUCTOR THAT WAS BEHIND HIM THAT HE 'TURNED BEHIND YOU A LITTLE CLOSER THAN HE SHOULD HAVE'. MID DOWNWIND I LOOKED BEHIND ME TO SEE HOW BUSY IT WAS SO I COULD JUDGE MY BASE TURN TO KEEP A GOOD FLOW OF THE TFC IN THE PATTERN. I SAW AN SMA VERY CLOSE TO ME IN THE DOWNWIND. I WOULD HAVE GUESSED HE WAS 500-1000' BEHIND ME. I THOUGHT THE SMA WAS JUST BEING A LITTLE FUNNY AND PLAYING GAMES WITH ME. HE HAD (I BELIEVE) TO HAVE SEEN ME IN THE DOWNWIND BECAUSE HE'S DIRECTLY BEHIND ME AT AN ALT NOT MORE THAN 10' FROM MINE. SO FIGURING HE SAW ME I PROCEEDED TO FLY MY DOWNWIND. I DID HEAR HIM CALL A LEFT TURN FOR AN E DEP. I CALLED A BASE TURN AT THE STANDARD 45 DEG OFF MY SHOULDER FROM THE TOUCHDOWN POINT IN THE DOWNWIND. I AND MY STUDENT LOOKED FOR TFC AND PROCEEDED TO TURN THE BASE LEG. WHEN WE ROLLED OUT OF OUR BANK THERE WAS THE SMA 200-300' JUST A LITTLE BIT HIGHER THAN US (100') AWAY FROM US. I BANKED SEMI STEEPLY TO THE RIGHT AND ADDED SOME MORE PITCH TO THE DSCNT ATTITUDE.

Data retrieved from NASA's ASRS site as of August 2007 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.