Narrative:

Small aircraft X was southbound navigating between the rosewood VOR (rod) and the falmouth VOR (flm) level at 6000 MSL. Small aircraft Y was nwbnd from huntingdon, direct to ft wayne, in (approximately 330 degree) at 6000 MSL. I was working the south arrival departure in the dayton TRACON with the south final/satellite radar position combined to my position. Due to the close proximity of all these airports to one another my attention was solely placed on the separation of the numerous arrs and overflts. Small aircraft Y had transversed to within 10 mi of our west arrival's airspace at which time I initiated the automated handoff. When small aircraft Y was 5 mi from the west arrival's airspace I observed the automated handoff was accomplished. I then switched small aircraft Y to the west arrival's frequency. After switching frequency, I then observed small aircraft X on a converging course. I issued a left turn to small aircraft X for traffic and received no response. I immediately reissued the turn and received an acknowledgement. As small aircraft X turned to the left I observed the conflict alert alarm. The conflict alert parameters have been returned to the point where it alarms after separation is lost. It needs to be expanded out to a point that alerts you to a conflict. It only alerts you now that separation is already lost. On occasions it hasn't even alarmed in its present parameters.

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Original NASA ASRS Text

Title: SMA HANDED OFF TO THE ADJACENT CTLR CAME IN CLOSE PROX TO ANOTHER SMA ON FREQ.

Narrative: SMA X WAS SBND NAVING BTWN THE ROSEWOOD VOR (ROD) AND THE FALMOUTH VOR (FLM) LEVEL AT 6000 MSL. SMA Y WAS NWBND FROM HUNTINGDON, DIRECT TO FT WAYNE, IN (APPROX 330 DEG) AT 6000 MSL. I WAS WORKING THE S ARR DEP IN THE DAYTON TRACON WITH THE S FINAL/SATELLITE RADAR POS COMBINED TO MY POS. DUE TO THE CLOSE PROX OF ALL THESE ARPTS TO ONE ANOTHER MY ATTN WAS SOLELY PLACED ON THE SEPARATION OF THE NUMEROUS ARRS AND OVERFLTS. SMA Y HAD TRANSVERSED TO WITHIN 10 MI OF OUR W ARR'S AIRSPACE AT WHICH TIME I INITIATED THE AUTOMATED HDOF. WHEN SMA Y WAS 5 MI FROM THE W ARR'S AIRSPACE I OBSERVED THE AUTOMATED HDOF WAS ACCOMPLISHED. I THEN SWITCHED SMA Y TO THE W ARR'S FREQ. AFTER SWITCHING FREQ, I THEN OBSERVED SMA X ON A CONVERGING COURSE. I ISSUED A L TURN TO SMA X FOR TFC AND RECEIVED NO RESPONSE. I IMMEDIATELY REISSUED THE TURN AND RECEIVED AN ACKNOWLEDGEMENT. AS SMA X TURNED TO THE LEFT I OBSERVED THE CONFLICT ALERT ALARM. THE CONFLICT ALERT PARAMETERS HAVE BEEN RETURNED TO THE POINT WHERE IT ALARMS AFTER SEPARATION IS LOST. IT NEEDS TO BE EXPANDED OUT TO A POINT THAT ALERTS YOU TO A CONFLICT. IT ONLY ALERTS YOU NOW THAT SEPARATION IS ALREADY LOST. ON OCCASIONS IT HASN'T EVEN ALARMED IN ITS PRESENT PARAMETERS.

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.