Narrative:

Inbound to dal on the bowie one arrival. After deviating around some weather; we were cleared direct to gregs and the gregs 6 arrival. We were then given a descent clearance to cross gregs at 10;000 ft. The FMS was programmed and calculated our descent rate to be 2;000 FPM. While I was loading in approach numbers; ATC told us to 'turn right immediately and climb to 17;000'. We were approximately 18 miles west of gregs intersection. I looked up at the altimeter and saw 16;300 descending. The first officer disconnected the autopilot and began a climbing right turn. At the same time the ATC controller finished that clearance; the TCAS called 'traffic' and very shortly after that the TCAS called 'climb'. We ended up climbing to about 17;500 and about a 90 degree turn to the right. After the conflict was resolved; we were issued a new clearance back to gregs. The ATC controller was noticeably shaken after the event. He apologized to us and was relieved shortly after that. The ATC controller caught his mistake only seconds before the TCAS alerted us. If the controller had not caught his mistake; I am confident the TCAS alone would have prevented a collision. There was a loss of separation during this event. I did not see the other aircraft but the TCAS showed the aircraft at 400 ft below us at the closest point. I believe the other aircraft involved in the incident initiated a TCAS descent.

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Original NASA ASRS Text

Title: CL604 Flight Crew experiences a TCAS RA just after commencing descent per ATC instructions. Controller issues climb and turn instructions just before the TCAS alert.

Narrative: Inbound to DAL on the BOWIE ONE arrival. After deviating around some weather; we were cleared direct to GREGS and the GREGS 6 arrival. We were then given a descent clearance to cross GREGS at 10;000 FT. The FMS was programmed and calculated our descent rate to be 2;000 FPM. While I was loading in approach numbers; ATC told us to 'turn right immediately and climb to 17;000'. We were approximately 18 miles west of GREGS Intersection. I looked up at the altimeter and saw 16;300 descending. The First Officer disconnected the autopilot and began a climbing right turn. At the same time the ATC Controller finished that clearance; the TCAS called 'TRAFFIC' and very shortly after that the TCAS called 'CLIMB'. We ended up climbing to about 17;500 and about a 90 degree turn to the right. After the conflict was resolved; we were issued a new clearance back to GREGS. The ATC Controller was noticeably shaken after the event. He apologized to us and was relieved shortly after that. The ATC Controller caught his mistake only seconds before the TCAS alerted us. If the Controller had not caught his mistake; I am confident the TCAS alone would have prevented a collision. There was a loss of separation during this event. I did not see the other aircraft but the TCAS showed the aircraft at 400 FT below us at the closest point. I believe the other aircraft involved in the incident initiated a TCAS descent.

Data retrieved from NASA's ASRS site as of April 2012 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.