Narrative:

The TCASII has no way of knowing the traffic it is warning about will stop its descent. The conflict was due to an ATC controled aircraft descending to 11000 ft at our 1 O'clock position. Although we had aircraft in sight we were not sure that traffic was the aircraft giving us the RA and therefore followed its direction.

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Original NASA ASRS Text

Title: ACR MLG ALTDEV EXCURSION FROM CLRNC ALT IN RESPONSE TO TCASII RA.

Narrative: THE TCASII HAS NO WAY OF KNOWING THE TFC IT IS WARNING ABOUT WILL STOP ITS DSCNT. THE CONFLICT WAS DUE TO AN ATC CTLED ACFT DSNDING TO 11000 FT AT OUR 1 O'CLOCK POS. ALTHOUGH WE HAD ACFT IN SIGHT WE WERE NOT SURE THAT TFC WAS THE ACFT GIVING US THE RA AND THEREFORE FOLLOWED ITS DIRECTION.

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.