Narrative:

Air carrier X was inbound to cvg. I descended aircraft from 11000 ft to 10000 ft for runway 36C; and handed off aircraft; then switched to frequency 119.7. In about 10 mi; a target popped up opposite direction level at 10000 ft heading directly for air carrier X. Air carrier X was issued merging target procedures and climbed to 11000 ft. About 5 mi after traffic merged; the target disappeared. The false target was on the same beacon code. This was not known until after the traffic merged. At the time of the incident; all involved thought it was real; live traffic. False targets are getting more numerous at cvg. I consider this to be both hazardous and unsafe!

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Original NASA ASRS Text

Title: CVG CTLR EXPERIENCED CONFLICT ALERT AT 10000 FT WITH OPPOSITE DIRECTION TFC BELIEVED TO BE A FALSE TARGET.

Narrative: ACR X WAS INBOUND TO CVG. I DSNDED ACFT FROM 11000 FT TO 10000 FT FOR RWY 36C; AND HANDED OFF ACFT; THEN SWITCHED TO FREQ 119.7. IN ABOUT 10 MI; A TARGET POPPED UP OPPOSITE DIRECTION LEVEL AT 10000 FT HEADING DIRECTLY FOR ACR X. ACR X WAS ISSUED MERGING TARGET PROCS AND CLBED TO 11000 FT. ABOUT 5 MI AFTER TFC MERGED; THE TARGET DISAPPEARED. THE FALSE TARGET WAS ON THE SAME BEACON CODE. THIS WAS NOT KNOWN UNTIL AFTER THE TFC MERGED. AT THE TIME OF THE INCIDENT; ALL INVOLVED THOUGHT IT WAS REAL; LIVE TFC. FALSE TARGETS ARE GETTING MORE NUMEROUS AT CVG. I CONSIDER THIS TO BE BOTH HAZARDOUS AND UNSAFE!

Data retrieved from NASA's ASRS site as of January 2009 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.