Narrative:

Bwi approach advised us of traffic at 10 O'clock, at 11500 ft. We were at 12000 ft. I saw the traffic and was given visual descent clearance through the 11500 ft traffic's altitude. I was in the descent (vsi 1200 to 1500 ft down) when we got a TCASII RA to climb. When I looked at the altitude, it was going through 11500 ft and the visual traffic and TCASII traffic was now at 9 O'clock. As I was already through the altitude of the traffic, I decided to continue the descent to my assigned altitude of 10000 ft. We did not have to maneuver out of the traffic's way other than descend. Because of the fact that I already was in a 1200 to 1500 ft descent when the TCASII RA sounded, I felt that climbing back up through his altitude was not necessary. The traffic was at 9 O'clock and moving further behind my direction of flight, also. Supplemental information from acn 321051: baltimore approach gave us a traffic call for an islander. We did not know the direction of the aircraft until receiving the RA. It was heading westerly, toward us. We should not have descended until passing the aircraft.

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Original NASA ASRS Text

Title: WHILE MAINTAINING VISUAL SEPARATION WITH ANOTHER ACFT DURING A DSCNT CLRNC, AN ACR FLC RECEIVED A TCASII RA.

Narrative: BWI APCH ADVISED US OF TFC AT 10 O'CLOCK, AT 11500 FT. WE WERE AT 12000 FT. I SAW THE TFC AND WAS GIVEN VISUAL DSCNT CLRNC THROUGH THE 11500 FT TFC'S ALT. I WAS IN THE DSCNT (VSI 1200 TO 1500 FT DOWN) WHEN WE GOT A TCASII RA TO CLB. WHEN I LOOKED AT THE ALT, IT WAS GOING THROUGH 11500 FT AND THE VISUAL TFC AND TCASII TFC WAS NOW AT 9 O'CLOCK. AS I WAS ALREADY THROUGH THE ALT OF THE TFC, I DECIDED TO CONTINUE THE DSCNT TO MY ASSIGNED ALT OF 10000 FT. WE DID NOT HAVE TO MANEUVER OUT OF THE TFC'S WAY OTHER THAN DSND. BECAUSE OF THE FACT THAT I ALREADY WAS IN A 1200 TO 1500 FT DSCNT WHEN THE TCASII RA SOUNDED, I FELT THAT CLBING BACK UP THROUGH HIS ALT WAS NOT NECESSARY. THE TFC WAS AT 9 O'CLOCK AND MOVING FURTHER BEHIND MY DIRECTION OF FLT, ALSO. SUPPLEMENTAL INFO FROM ACN 321051: BALTIMORE APCH GAVE US A TFC CALL FOR AN ISLANDER. WE DID NOT KNOW THE DIRECTION OF THE ACFT UNTIL RECEIVING THE RA. IT WAS HDG WESTERLY, TOWARD US. WE SHOULD NOT HAVE DSNDED UNTIL PASSING THE ACFT.

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