Narrative:

I was working local control east. I observed a target on the asde-X display that I confirmed was false as I looked out the window. I informed flm of the target. I cleared a jet for takeoff and as the aircraft rolled it set off the alarms on asde-X indicating a potential collision. This situation was logged. Exact same occurrences for each of the next 2 departures. Finally after I demanded the equipment be taken off line or I be relieved of the position the flm put the asde-X in limited mode. When the false target disappeared; the asde-X was put back in full operation. Problem was never diagnosed or fixed.

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Original NASA ASRS Text

Title: CLT CTLR DESCRIBED INCIDENT WHEN NO TFC WAS OBSERVED ON THE DEP RWY BUT ASDE-X ALARMED ON FALSE TARGET WITH THREE DEP ACFT.

Narrative: I WAS WORKING LCL CTL E. I OBSERVED A TARGET ON THE ASDE-X DISPLAY THAT I CONFIRMED WAS FALSE AS I LOOKED OUT THE WINDOW. I INFORMED FLM OF THE TARGET. I CLRED A JET FOR TKOF AND AS THE ACFT ROLLED IT SET OFF THE ALARMS ON ASDE-X INDICATING A POTENTIAL COLLISION. THIS SITUATION WAS LOGGED. EXACT SAME OCCURRENCES FOR EACH OF THE NEXT 2 DEPS. FINALLY AFTER I DEMANDED THE EQUIP BE TAKEN OFF LINE OR I BE RELIEVED OF THE POS THE FLM PUT THE ASDE-X IN LIMITED MODE. WHEN THE FALSE TARGET DISAPPEARED; THE ASDE-X WAS PUT BACK IN FULL OP. PROB WAS NEVER DIAGNOSED OR FIXED.

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.