Narrative:

Small aircraft X en route to gsp from over mcn at 7000' said something about traffic which was unreadable just as he was being switched to ZTL ahn lo sector. Traffic was extremely heavy. At the time I was working mcn hi at mcn approach. Small aircraft X was transitioning northeast bound with 2 southbound aircraft at 7000' MSL. I was busy transitioning 2 departure off mcn and 1 inbound into atl approach. I was aware of all of the aircraft and observed that small aircraft X would pass behind both aircraft. There was northbound traffic at 6000 and 8000', wbound traffic at 10000'. Also, one aircraft southbound at 9000'. One departure off mcn was climbing above 10000' and the aircraft inbound to ATC was descending from 11000' to 5000'. All these aircraft were in the northeast quadrant of mcn's airspace. Small aircraft X passed well clear of aircraft Y I was applying crossing and diverging procedures as per handbook, 7110.65 para 5-73. In my opinion, the course of small aircraft X would pass behind aircraft Y. After this incident had passed and I was relieved, I thought about what small aircraft X may have said and mentioned it to my supervisor. We changed the tape and listened to the transmission. Small aircraft X's transmission was very garbled and not really readable. We asked ZTL data systems to extract data on both aircraft, but the beacon on aircraft Y was in CST from time of initial handoff up near gloss intersection till 3 or 4 mins after small aircraft X had been switched. I was observing primary, which subsequently retagged as aircraft Y which passed clear of small aircraft X. I observed no other traffic or targets in the vicinity of small aircraft X. I believe this situation was not helped by short staffing and the inability to track certain xponders which result in too many non beacons. I intended to take further action and possible issue a vector, but was distracted. The supervisor was coordinating, as I had asked for help, but he was busy with coordinating track updates and coordinating ARTS tags which were on the high scope but were at low altitudes and should have been on my scope.

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Original NASA ASRS Text

Title: POSSIBLE LESS THAN STANDARD SEPARATION. POSSIBLE SYSTEM ERROR.

Narrative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

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.