Narrative:

I was returning to the airport from the south listening to CTAF. There were 2 or 3 airplanes in the pattern doing touch and goes. I entered a 45 downwind; left traffic for runway 27.there was one plane just finishing his crosswind and entering downwind behind me; one airplane on final which I could see landing; one airplane in front of me on downwind. I did not see him. There was another plane overhead at 7;000 circling waiting to eventually get in the pattern with an overhead entry.the plane in front of me called left base for runway 27 and I continued downwind after passing abeam the runway end. When I heard the front plane call final I started my base leg. I still did not see him. When I was almost inline with runway 27 I started to turn final and heard the previous plane call short final and at the same time I saw him. I was to his left and below him and within 50 to 100 ft.I moved slightly left; aborted my landing and flew upwind to stay in the pattern. It did not require an extreme maneuver on my part. (The other pilot and I talked about it later on the ground.) I felt that it was getting too chaotic so I departed the pattern and several minutes later reentered left downwind for an uneventful landing.in retrospect I realize I was flying the traffic pattern by rote and that was a mistake. Since I didn't have visual contact I should have aborted the entire approach and reentered.

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Original NASA ASRS Text

Title: The pilot of a homebuilt aircraft suffered a NMAC with a single engine Cessna on short final at an uncontrolled airport. Both pilots were utilizing CTAF but never had visual contact with one another.

Narrative: I was returning to the airport from the south listening to CTAF. There were 2 or 3 airplanes in the pattern doing touch and goes. I entered a 45 downwind; left traffic for Runway 27.There was one plane just finishing his crosswind and entering downwind behind me; one airplane on final which I could see landing; one airplane in front of me on downwind. I did not see him. There was another plane overhead at 7;000 circling waiting to eventually get in the pattern with an overhead entry.The plane in front of me called left base for Runway 27 and I continued downwind after passing abeam the runway end. When I heard the front plane call final I started my base leg. I still did not see him. When I was almost inline with Runway 27 I started to turn final and heard the previous plane call short final and at the same time I saw him. I was to his left and below him and within 50 to 100 FT.I moved slightly left; aborted my landing and flew upwind to stay in the pattern. It did not require an extreme maneuver on my part. (The other pilot and I talked about it later on the ground.) I felt that it was getting too chaotic so I departed the pattern and several minutes later reentered left downwind for an uneventful landing.In retrospect I realize I was flying the traffic pattern by rote and that was a mistake. Since I didn't have visual contact I should have aborted the entire approach and reentered.

Data retrieved from NASA's ASRS site as of July 2013 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.