Narrative:

I was working both aircraft. I had issued a descent clearance to aircraft X in order to get underneath aircraft Y. An unidented class B violator caused aircraft X's TCAS to issue an RA climb. Aircraft X climbed into aircraft Y. I issued aircraft Y a turn until visual separation was established.

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Original NASA ASRS Text

Title: D10 CTLR EXPERIENCED SEPARATION LOSS AT 3500 FT WHEN IFR ACFT RESPONDED TO TCAS RA OF A CLASS B VIOLATOR LOSING SEPARATION WITH ANOTHER ACFT.

Narrative: I WAS WORKING BOTH ACFT. I HAD ISSUED A DSCNT CLRNC TO ACFT X IN ORDER TO GET UNDERNEATH ACFT Y. AN UNIDENTED CLASS B VIOLATOR CAUSED ACFT X'S TCAS TO ISSUE AN RA CLB. ACFT X CLBED INTO ACFT Y. I ISSUED ACFT Y A TURN UNTIL VISUAL SEPARATION WAS ESTABLISHED.

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.