Narrative:

Was instructed by flm (front line manager) to split off sector 61 from 82 (lee high from ink/lee high 82/61). Three military areas active; and more traffic on sector 61 than 82; but when the split off was done; half of the aircraft were on the wrong frequency and the d-side stayed on the other sector. Had air carrier X at a temporary altitude of FL340 (showing FL360 as requested final) for overhead traffic at FL360; rerouted both those two aircraft to get them horizontally separated. Air carrier Y was east northeast inbound to dfw at FL330. Air carrier X had additional crossing traffic up ahead at FL340; so I cleared air carrier X on up to FL360. Air carrier X told me he couldn't take FL360. I told air carrier X to maintain FL340 and to expect a 1K foot change up ahead for that crossing traffic. At the time I was having trouble hearing the pilot of air carrier X (another pilot on frequency told him to 'speak up'). Later; air carrier X said he could take FL350 so I climbed air carrier X to FL350; he came right back and said something about his air conditioner not working and was requesting FL250 not FL350. I assigned air carrier X FL250 and was looking ahead and to the east of his route but did not adequately scan southwest; did not mentally process the conflict with air carrier Y at FL330. A few minutes later air carrier Y asked me who the traffic was that passed over close to him. I saw the air carrier X behind air carrier Y; and diverging away from the air carrier Y's route starting his descent and told the air carrier Y it must have been air carrier X behind him. Air carrier Y said he saw the target on TCAS; (did not do an RA); and it seemed close. I told him I only needed five miles and the air carrier X was more than that from him; not realizing the air carrier X had actually gotten closer than that. My traffic scan was obviously insufficient; because I did not see the error develop or happen; conflict alert never activated. Didn't know a loss of separation actually occurred until 8-10 minutes later when flm asked me about 'the air carrier X and air carrier Y'. These sectors are rarely split; and if so; it's because of heavy volume; complexity or weather. As stated earlier; I hadn't split off or worked this sector split in several months. Because of the infrequency; it's always cumbersome; because the flm's usually wait till it's really too late; they should just use a tracker on the 2 sectors combined; it would be better to have an extra set of eyes and coordinator because 90 percent of the traffic will be worked by both of the sectors anyway; and it's very cumbersome to get them on the correct frequency and call all the surrounding sectors to notify them of the split; drawing moas/atcaas; setting up the sector map/altitudes/uret; etc all takes time. Don't misunderstand; the sectors really don't need to be spilt very often because there isn't the demand; but if your going to split it; do it soon enough so everything is not rushed. I really felt pressured and rushed by the flm to get it split; even during the briefing; and I should have 'inherited' the d-side because I had more going on my side when it was split; I could have really used the help. But; I should have asked for help because I was really feeling 'behind the curve' and not 'in the zone' (per CRM training) from the moment I split the sector off; with this feeling of trying to catch up.

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Original NASA ASRS Text

Title: ZFW Controller experienced loss of separation event; the reporter indicating the in frequent sector de-combination effort was late given the traffic build-up and consequently caused an increase in workload and confusion.

Narrative: Was instructed by FLM (Front Line Manager) to split off Sector 61 from 82 (LEE high from INK/LEE high 82/61). Three military areas active; and more traffic on Sector 61 than 82; but when the split off was done; half of the aircraft were on the wrong frequency and the D-side stayed on the other sector. Had Air Carrier X at a temporary altitude of FL340 (showing FL360 as requested final) for overhead traffic at FL360; rerouted both those two aircraft to get them horizontally separated. Air Carrier Y was east northeast inbound to DFW at FL330. Air Carrier X had additional crossing traffic up ahead at FL340; so I cleared Air Carrier X on up to FL360. Air Carrier X told me he couldn't take FL360. I told Air Carrier X to maintain FL340 and to expect a 1K foot change up ahead for that crossing traffic. At the time I was having trouble hearing the pilot of Air Carrier X (another pilot on frequency told him to 'speak up'). Later; Air Carrier X said he could take FL350 so I climbed Air Carrier X to FL350; he came right back and said something about his air conditioner not working and was requesting FL250 NOT FL350. I assigned Air Carrier X FL250 and was looking ahead and to the east of his route but did not adequately scan southwest; did not mentally process the conflict with Air Carrier Y at FL330. A few minutes later Air Carrier Y asked me who the traffic was that passed over close to him. I saw the Air Carrier X behind Air Carrier Y; and diverging away from the Air Carrier Y's route starting his descent and told the Air Carrier Y it must have been Air Carrier X behind him. Air Carrier Y said he saw the target on TCAS; (did not do an RA); and it seemed close. I told him I only needed five miles and the Air Carrier X was more than that from him; not realizing the Air Carrier X had actually gotten closer than that. My traffic scan was obviously insufficient; because I did not see the error develop or happen; conflict alert never activated. Didn't know a loss of separation actually occurred until 8-10 minutes later when FLM asked me about 'the Air Carrier X and Air Carrier Y'. These sectors are rarely split; and if so; it's because of heavy volume; complexity or weather. As stated earlier; I hadn't split off or worked this sector split in several months. Because of the infrequency; it's always cumbersome; because the FLM's usually wait till it's really too late; they should just use a tracker on the 2 sectors combined; it would be better to have an extra set of eyes and coordinator because 90 percent of the traffic will be worked by both of the sectors anyway; and it's very cumbersome to get them on the correct frequency and call all the surrounding sectors to notify them of the split; drawing MOAs/ATCAAs; setting up the sector map/altitudes/URET; etc all takes time. Don't misunderstand; the sectors really don't need to be spilt very often because there isn't the demand; but if your going to split it; do it soon enough so everything is not rushed. I really felt pressured and rushed by the FLM to get it split; even during the briefing; and I should have 'inherited' the D-side because I had more going on my side when it was split; I could have really used the help. But; I should have asked for help because I was really feeling 'behind the curve' and not 'in the zone' (per CRM training) from the moment I split the sector off; with this feeling of trying to catch up.

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.