Narrative:

I was in a direct cruise from ZZZ toward ZZZ1 and was aware of traffic to my 3 o'clock ten miles in front of me on heading in the same general direction. I didn't think anything of it as he was 500 ft. Below me and still a ways away. As I got closer I had my descent profile pulled up on my GPS to my destination. When the profile said to start my descent at 500 ft. Per minute; I did not notice any traffic by visual cues and started down. I then checked and saw the same traffic as before on ads-B what seemed to be right below me. I quickly banked over to the left away from the traffic and headed in a different heading to create separation. I would say the closest we came together was within a distance of in between 0.5 to 1 mile laterally and within 300 ft. Vertically according to the ads-B read out on the traffic page. I never had a visual until after the evasive action was taken. I was distracted at the time of the incident and did not see the traffic before I started my descent. It seemed like a close call; however I do not remember ever seeing a traffic alert that usually pops up on the GPS or fore-flight. It definitely seemed like it was close enough; however I was glad to have seen the traffic on the map so I could take evasive action. I am not sure if the other traffic ever saw me or not. He was at 5;000 ft. While I started my descent from 5;500 ft. I assume the traffic was on an IFR flight plan but I am not sure; he never deviated from his course. I was the faster aircraft and therefore he had the right of way; however I did not see him as he was below me under my right wing.

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Original NASA ASRS Text

Title: Mooney-20C pilot reported airborne conflict during descent with another aircraft visible on ADS-B.

Narrative: I was in a direct cruise from ZZZ toward ZZZ1 and was aware of traffic to my 3 o'clock ten miles in front of me on heading in the same general direction. I didn't think anything of it as he was 500 ft. below me and still a ways away. As I got closer I had my descent profile pulled up on my GPS to my destination. When the profile said to start my descent at 500 ft. per minute; I did not notice any traffic by visual cues and started down. I then checked and saw the same traffic as before on ADS-B what seemed to be right below me. I quickly banked over to the left away from the traffic and headed in a different heading to create separation. I would say the closest we came together was within a distance of in between 0.5 to 1 mile laterally and within 300 ft. vertically according to the ADS-B read out on the traffic page. I never had a visual until after the evasive action was taken. I was distracted at the time of the incident and did not see the traffic before I started my descent. It seemed like a close call; however I do not remember ever seeing a traffic alert that usually pops up on the GPS or Fore-Flight. It definitely seemed like it was close enough; however I was glad to have seen the traffic on the map so I could take evasive action. I am not sure if the other traffic ever saw me or not. He was at 5;000 ft. while I started my descent from 5;500 ft. I assume the traffic was on an IFR flight plan but I am not sure; he never deviated from his course. I was the faster aircraft and therefore he had the right of way; however I did not see him as he was below me under my right wing.

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.