Narrative:

We were being radar vectored by den approach control and given a clearance to descend to and maintain 11000 ft MSL. Approach was very busy, as usual, in the terminal area. The first officer was flying while I worked the radios. I mentioned to approach that I noticed a widebody transport climbing out on departure at our 1-2 O'clock position. The TCASII showed the aircraft climbing toward our altitude. It then started a climbing right turn to our direction. Approach came back and said 'climb immediately to 15000 ft.' the TCASII showed red in the climb area of the vvi and said 'monitor vertical speed.' had we climbed expeditiously to 15000 ft MSL, we would have had a conflict with the climbing traffic. The controller issued what was considered the correct action in her mind, however, if we had followed the controller's direction and ignored the TCASII, we would have had a very close call. We maintained altitude assigned 11000 ft MSL and told the controller we would maintain visual separation with the climbing aircraft. This is yet another example and proof pilots should follow the guidance of TCASII when faced with a possible conflict, especially when in IMC conditions when visual contact is not acquired.

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Original NASA ASRS Text

Title: FLC OF AN MLG ACR ACFT RESPONDED TO TCASII RA AND THE VISUAL SIGHTING OF THE CONFLICTING ACFT RATHER THAN CLB AS INSTRUCTED BY ATC FOR EVASIVE ACTION.

Narrative: WE WERE BEING RADAR VECTORED BY DEN APCH CTL AND GIVEN A CLRNC TO DSND TO AND MAINTAIN 11000 FT MSL. APCH WAS VERY BUSY, AS USUAL, IN THE TERMINAL AREA. THE FO WAS FLYING WHILE I WORKED THE RADIOS. I MENTIONED TO APCH THAT I NOTICED A WDB CLBING OUT ON DEP AT OUR 1-2 O'CLOCK POS. THE TCASII SHOWED THE ACFT CLBING TOWARD OUR ALT. IT THEN STARTED A CLBING R TURN TO OUR DIRECTION. APCH CAME BACK AND SAID 'CLB IMMEDIATELY TO 15000 FT.' THE TCASII SHOWED RED IN THE CLB AREA OF THE VVI AND SAID 'MONITOR VERT SPD.' HAD WE CLBED EXPEDITIOUSLY TO 15000 FT MSL, WE WOULD HAVE HAD A CONFLICT WITH THE CLBING TFC. THE CTLR ISSUED WHAT WAS CONSIDERED THE CORRECT ACTION IN HER MIND, HOWEVER, IF WE HAD FOLLOWED THE CTLR'S DIRECTION AND IGNORED THE TCASII, WE WOULD HAVE HAD A VERY CLOSE CALL. WE MAINTAINED ALT ASSIGNED 11000 FT MSL AND TOLD THE CTLR WE WOULD MAINTAIN VISUAL SEPARATION WITH THE CLBING ACFT. THIS IS YET ANOTHER EXAMPLE AND PROOF PLTS SHOULD FOLLOW THE GUIDANCE OF TCASII WHEN FACED WITH A POSSIBLE CONFLICT, ESPECIALLY WHEN IN IMC CONDITIONS WHEN VISUAL CONTACT IS NOT ACQUIRED.

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.