Narrative:

ZFW sector 47 was heavily impacted with WX. ZFW sector 47 handles inbound aircraft to dfw. Dfw was closed for quite some time prior to this event. At the time around the event; we had just come out of no-notice holding and were transition to 20 mi in trail spacing on dfw arrs. We were still holding for dal. The sector was staffed by a radar controller; radar associate and a handoff. WX was scattered around the sector and the adjoining sectors and was severe. This WX was causing numerous deviations. No tmu restrs were in place to space aircraft inbound to dfw except the restrs by dfw TRACON for 15 mi in trail. So sector 47 was getting numerous aircraft from adjoining sectors with no in-trail spacing. I believe the adjoining sectors were about as busy as I was; so we limited our requests of them to spin aircraft for us. Fatigue by any member of the radar team was not a factor. Aircraft X checked on frequency at FL410 inbound to dal. After being advised to hold at zanto intersection; he advised me he wanted to go to ftw. Later I cleared him to ftw and descended him to FL390. He came back at the last min and asked to hold for dal instead. Aircraft Y was an overflt inbound to dwh (houston metropolitan area) and was at FL390. Aircraft X and aircraft Y responded to a TCAS RA and were instantly separated by the FAA standard separation criteria. If they would not have responded to the RA's and I would have done nothing (which I would have tried); the aircraft would have been about .1 or .2 mi lateral and no vertical. The radar team has lots of experience and have handled these kinds of activities before without incident. Why we missed this one; I don't know; except for 1 thing that keeps bothering me. Management has within the last yr mandated lots of redundancy -- meaning; on sectors that used to be staffed by 1 controller (no radar associate or handoff) are now being required to have 2 or more controllers. This has caused a small degrading of the individual controller's speed and scan rate because you're never as busy as you once were. At the same time; management and tmu haven't changed their practices to try to limit the aircraft in a sector that is heavily impacted with WX and management is limited in their ability to understand what needs to be done when these situations occur. Management; after the error; has limited us to 1 first line supervisor; waiting to listen to solutions from the controller team that may prevent these types of errors.

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Original NASA ASRS Text

Title: ZFW CTLR DESCRIBED TCAS RA EVENT AT FL390; SEPARATION MAINTAINED DUE TO TCAS RESPONSE/CTLR ACTIONS; FAA OPS POLICY CITED AS CAUSAL FACTORS.

Narrative: ZFW SECTOR 47 WAS HEAVILY IMPACTED WITH WX. ZFW SECTOR 47 HANDLES INBOUND ACFT TO DFW. DFW WAS CLOSED FOR QUITE SOME TIME PRIOR TO THIS EVENT. AT THE TIME AROUND THE EVENT; WE HAD JUST COME OUT OF NO-NOTICE HOLDING AND WERE TRANSITION TO 20 MI IN TRAIL SPACING ON DFW ARRS. WE WERE STILL HOLDING FOR DAL. THE SECTOR WAS STAFFED BY A RADAR CTLR; RADAR ASSOCIATE AND A HDOF. WX WAS SCATTERED AROUND THE SECTOR AND THE ADJOINING SECTORS AND WAS SEVERE. THIS WX WAS CAUSING NUMEROUS DEVS. NO TMU RESTRS WERE IN PLACE TO SPACE ACFT INBOUND TO DFW EXCEPT THE RESTRS BY DFW TRACON FOR 15 MI IN TRAIL. SO SECTOR 47 WAS GETTING NUMEROUS ACFT FROM ADJOINING SECTORS WITH NO IN-TRAIL SPACING. I BELIEVE THE ADJOINING SECTORS WERE ABOUT AS BUSY AS I WAS; SO WE LIMITED OUR REQUESTS OF THEM TO SPIN ACFT FOR US. FATIGUE BY ANY MEMBER OF THE RADAR TEAM WAS NOT A FACTOR. ACFT X CHKED ON FREQ AT FL410 INBOUND TO DAL. AFTER BEING ADVISED TO HOLD AT ZANTO INTXN; HE ADVISED ME HE WANTED TO GO TO FTW. LATER I CLRED HIM TO FTW AND DSNDED HIM TO FL390. HE CAME BACK AT THE LAST MIN AND ASKED TO HOLD FOR DAL INSTEAD. ACFT Y WAS AN OVERFLT INBOUND TO DWH (HOUSTON METRO AREA) AND WAS AT FL390. ACFT X AND ACFT Y RESPONDED TO A TCAS RA AND WERE INSTANTLY SEPARATED BY THE FAA STANDARD SEPARATION CRITERIA. IF THEY WOULD NOT HAVE RESPONDED TO THE RA'S AND I WOULD HAVE DONE NOTHING (WHICH I WOULD HAVE TRIED); THE ACFT WOULD HAVE BEEN ABOUT .1 OR .2 MI LATERAL AND NO VERT. THE RADAR TEAM HAS LOTS OF EXPERIENCE AND HAVE HANDLED THESE KINDS OF ACTIVITIES BEFORE WITHOUT INCIDENT. WHY WE MISSED THIS ONE; I DON'T KNOW; EXCEPT FOR 1 THING THAT KEEPS BOTHERING ME. MGMNT HAS WITHIN THE LAST YR MANDATED LOTS OF REDUNDANCY -- MEANING; ON SECTORS THAT USED TO BE STAFFED BY 1 CTLR (NO RADAR ASSOCIATE OR HDOF) ARE NOW BEING REQUIRED TO HAVE 2 OR MORE CTLRS. THIS HAS CAUSED A SMALL DEGRADING OF THE INDIVIDUAL CTLR'S SPD AND SCAN RATE BECAUSE YOU'RE NEVER AS BUSY AS YOU ONCE WERE. AT THE SAME TIME; MGMNT AND TMU HAVEN'T CHANGED THEIR PRACTICES TO TRY TO LIMIT THE ACFT IN A SECTOR THAT IS HEAVILY IMPACTED WITH WX AND MGMNT IS LIMITED IN THEIR ABILITY TO UNDERSTAND WHAT NEEDS TO BE DONE WHEN THESE SITUATIONS OCCUR. MGMNT; AFTER THE ERROR; HAS LIMITED US TO 1 FIRST LINE SUPVR; WAITING TO LISTEN TO SOLUTIONS FROM THE CTLR TEAM THAT MAY PREVENT THESE TYPES OF ERRORS.

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