Narrative:

While performing touch and go's in the pattern; [I] was directed by ATC to maintain 1;100 feet pattern altitude. On one departure off runway xx I was directed by ATC to extend my upwind 1 mile before starting crosswind turn. I complied with this ATC instruction. After I started my right turn for the right downwind leg; a cessna departing runway xx behind me turned crosswind and had a vector that appeared to be a collision course with me. My adsb alerted to me to this traffic conflict as well as my safety pilot who is also a certified pilot. A few seconds later; the adsb traffic conflict did not go away; and I had a visual of the conflicting traffic. I heard ATC ask the cessna if they had me in sight; and the cessna did not immediately respond. The cessna continued to appear larger in size; so to avoid a potential collision; I climbed in altitude to 1;500 feet. I estimated the cessna came within 500 feet of me. As I climbed to safety; I alerted ATC that I was climbing for a traffic conflict; the cessna who turned into my flight path and was a threat to me. ATC advised me to just maintain VFR and at that point I heard the cessna tell ATC they just got positive identification of me. This was after I made my escape maneuver. Continued on downwind at 1;500 feet and when ATC had the cessna behind me maneuver to leave enough space for me to descend back to 1;100 feet; ATC advised me to descend back to pattern altitude then cleared me for touch and go. No other conflicts after this one. It can't be overstated that adsb was a life saver today. Adsb is what first tipped me off about the conflicting traffic as well as its potential collision course.

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Original NASA ASRS Text

Title: PA-28 pilot reported an NMAC in the traffic pattern when the trailing departure pilot turned an early crosswind.

Narrative: While performing touch and go's in the pattern; [I] was directed by ATC to maintain 1;100 feet pattern altitude. On one departure off Runway XX I was directed by ATC to extend my upwind 1 mile before starting crosswind turn. I complied with this ATC instruction. After I started my right turn for the right downwind leg; a Cessna departing Runway XX behind me turned crosswind and had a vector that appeared to be a collision course with me. My ADSB alerted to me to this traffic conflict as well as my Safety Pilot who is also a certified pilot. A few seconds later; the ADSB traffic conflict did not go away; and I had a visual of the conflicting traffic. I heard ATC ask the Cessna if they had me in sight; and the Cessna did not immediately respond. The Cessna continued to appear larger in size; so to avoid a potential collision; I climbed in altitude to 1;500 feet. I estimated the Cessna came within 500 feet of me. As I climbed to safety; I alerted ATC that I was climbing for a traffic conflict; the Cessna who turned into my flight path and was a threat to me. ATC advised me to just maintain VFR and at that point I heard the Cessna tell ATC they just got positive ID of me. This was after I made my escape maneuver. Continued on downwind at 1;500 feet and when ATC had the Cessna behind me maneuver to leave enough space for me to descend back to 1;100 feet; ATC advised me to descend back to pattern altitude then cleared me for touch and go. No other conflicts after this one. It can't be overstated that ADSB was a life saver today. ADSB is what first tipped me off about the conflicting traffic as well as its potential collision course.

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.