Narrative:

We were cleared to 6000 ft. ATC called traffic at 11:30 O'clock position and 5600 ft; northbound. The controller stated it was an unverified VFR target and she wasn't talking to him. We observed the traffic on TCAS; but did not make visual contact. We received a TA from TCAS followed by the RA; 'monitor vertical speed.' I disengaged the autoplt to prepare for evasive action; if needed. We eventually made visual contact with the target. He passed 400 ft directly below us. TCAS gave us the 'clear of conflict' and ATC gave us a further descent. The flight continued normally without incident.

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Original NASA ASRS Text

Title: CRJ EXPERIENCES NMAC WITH VFR TRAFFIC WHILE ON DESCENT TO 6000 FT MSL. TCAS RA 'MONITOR VERTICAL SPEED' SUFFICED FOR SEPARATION.

Narrative: WE WERE CLRED TO 6000 FT. ATC CALLED TFC AT 11:30 O'CLOCK POS AND 5600 FT; NBOUND. THE CTLR STATED IT WAS AN UNVERIFIED VFR TARGET AND SHE WASN'T TALKING TO HIM. WE OBSERVED THE TFC ON TCAS; BUT DID NOT MAKE VISUAL CONTACT. WE RECEIVED A TA FROM TCAS FOLLOWED BY THE RA; 'MONITOR VERT SPD.' I DISENGAGED THE AUTOPLT TO PREPARE FOR EVASIVE ACTION; IF NEEDED. WE EVENTUALLY MADE VISUAL CONTACT WITH THE TARGET. HE PASSED 400 FT DIRECTLY BELOW US. TCAS GAVE US THE 'CLR OF CONFLICT' AND ATC GAVE US A FURTHER DSCNT. THE FLT CONTINUED NORMALLY WITHOUT INCIDENT.

Data retrieved from NASA's ASRS site as of May 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.