Narrative:

While on a left base leg for landing on runway 23; a conflict arose between me and another aircraft. I was flying a schweizer sgs 1-26 single seat glider. The other aircraft was a cessna 172 engaged in dual instruction. Two other aircraft were factors in the conflict: a high wing aircraft operated by a skydiving operation based on the field; and the towplane that launched me.I took off from runway 23 for a pattern tow. The tow was to 1200 ft AGL on the downwind leg and was unremarkable. I released and continued straight ahead on the downwind leg while the towplane dove to the left and also continued on the downwind for 23. In hindsight; I realize I should've made a right 360 degree turn for spacing from the tow plane; but I didn't. As a result I was hypervigilant about maintaining visual separation from the towplane. Both the towplane and I announced our positions and intentions to land on CTAF.the towplane landed well ahead of me. I turned left to enter the base leg and announced my position on CTAF. At that time I heard the cessna 172 announce that it was on a right base leg for 23. I began looking for the cessna and saw a high wing aircraft passing off my right in the opposite direction. Believing that plane to be the cessna; I stated on CTAF that I was 'just off your [the cessna's] right wingtip.' that plane was; in fact; the jump plane; but I didn't realize this until after landing.I continued on my base leg and continued scanning visually for traffic. I soon saw the cessna at my 2 o'clock and slightly above me; turning from right base to final quite close to me; and heard their announcement on CTAF. I executed an immediate; steep right 90 degree turn and announced the conflict on CTAF. The cessna acknowledged my radio call and executed a go around. I turned back towards the runway and landed uneventfully. The pilot of the cessna later told me that neither he nor his student ever saw me.after landing I realized that the airplane that had passed off my right had actually been the jump plane departing from runway 12; and that I hadn't heard the jump plane's takeoff announcement on CTAF. I presume I missed their takeoff announcement because I was so fixated on the towplane after release.in my opinion; factors leading to the near miss were: my failure to execute a separating turn upon release from the towplane; my subsequent fixation on the towplane's position causing me to miss the jump plane's takeoff announcement (and hence be unaware of their presence in the pattern); the jump plane's non-standard departure from a crossing runway; and the cessna's use of a non-standard traffic pattern. (The preferred pattern for runway 23 is left.) corrective actions were my steep right turn and the cessna's go around.

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Original NASA ASRS Text

Title: Glider pilot reported a NMAC while practicing in the pattern.

Narrative: While on a left base leg for landing on runway 23; a conflict arose between me and another aircraft. I was flying a Schweizer SGS 1-26 single seat glider. The other aircraft was a Cessna 172 engaged in dual instruction. Two other aircraft were factors in the conflict: a high wing aircraft operated by a skydiving operation based on the field; and the towplane that launched me.I took off from runway 23 for a pattern tow. The tow was to 1200 ft AGL on the downwind leg and was unremarkable. I released and continued straight ahead on the downwind leg while the towplane dove to the left and also continued on the downwind for 23. In hindsight; I realize I should've made a right 360 degree turn for spacing from the tow plane; but I didn't. As a result I was hypervigilant about maintaining visual separation from the towplane. Both the towplane and I announced our positions and intentions to land on CTAF.The towplane landed well ahead of me. I turned left to enter the base leg and announced my position on CTAF. At that time I heard the Cessna 172 announce that it was on a right base leg for 23. I began looking for the Cessna and saw a high wing aircraft passing off my right in the opposite direction. Believing that plane to be the Cessna; I stated on CTAF that I was 'just off your [the Cessna's] right wingtip.' That plane was; in fact; the jump plane; but I didn't realize this until after landing.I continued on my base leg and continued scanning visually for traffic. I soon saw the Cessna at my 2 o'clock and slightly above me; turning from right base to final quite close to me; and heard their announcement on CTAF. I executed an immediate; steep right 90 degree turn and announced the conflict on CTAF. The Cessna acknowledged my radio call and executed a go around. I turned back towards the runway and landed uneventfully. The pilot of the Cessna later told me that neither he nor his student ever saw me.After landing I realized that the airplane that had passed off my right had actually been the jump plane departing from runway 12; and that I hadn't heard the jump plane's takeoff announcement on CTAF. I presume I missed their takeoff announcement because I was so fixated on the towplane after release.In my opinion; factors leading to the near miss were: my failure to execute a separating turn upon release from the towplane; my subsequent fixation on the towplane's position causing me to miss the jump plane's takeoff announcement (and hence be unaware of their presence in the pattern); the jump plane's non-standard departure from a crossing runway; and the Cessna's use of a non-standard traffic pattern. (The preferred pattern for runway 23 is left.) Corrective actions were my steep right turn and the Cessna's go around.

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.