A controller described conflict event that resulted from a miscommunication during the combining of positions for late night operations.
Synopsis
A controller described conflict event that resulted from a miscommunication during the combining of positions for late night operations.
Narrative
The supervisor told air sector to set up for a normal combining for the mid-shift. I; and the air sector; thought the supervisor was to type the computer commands momentarily. I handed off and switched frequency of Air Carrier X to air sector (the where CKB combines to). The aircraft did not return to my frequency. Minutes later; air sector advised me that CKB was still open. It was at this time I heard the supervisor state 'False alarm; I'll move CKB now'. I guess he had delayed the computer commands as he perceived some heavier traffic. Since that sector is right next to CKB sector; and I did not get the aircraft back; I figured that air either pointed out the aircraft to CKB or handed the aircraft off to CKB. I was advised about fifteen minutes later that CKB only had a limited data block on Air Carrier X; and had descended Air Carrier Y through Air Carrier X's altitude. The air sector had turned Air Carrier X and CKB sector turned Air Carrier Y to ensure separation. Recommend keep handing off the aircraft to the 'normal' sector number until you see the aircraft flash to the combined sector.
Second reporter narrative
I was working the HLG/AIR sectors combined; altitudes ground to FL300. It was the end of the evening shift; and the supervisor advised he was going to combine CKB sector with AIR; normal operation. I advised I was ready and set up the sector appropriately. The supervisor went to the desk as if to combine the sectors and I took hand offs on Air Carrier X and another aircraft at FL360. After five to seven minutes the supervisor advised he was not going to combine the sectors. I thought the IRL radar controller would have shown the aircraft I took the hand offs on to the CKB controller. In fact; I noticed the CKB controller was not watching the aircraft at FL360 and forced it to his scope. I failed to notice the IRL controller had also failed to show the CKB controller Air Carrier X. A few minutes later the pilot of Air Carrier X asked if he had traffic; about the same time the conflict alert started flashing his aircraft with Air Carrier Y; which the data block showed FL350 descending to FL330. I answered the pilot yes; and immediately turned Air Carrier X twenty degrees to the right. The CKB controller turned the other flight; and separation was maintained. The CKB controller was unaware of Air Carrier X; only having a limited data block. If you are going to combine a sector; do so. Always address a hand off to the appropriate sector. If it is combined; it will flash at the appropriate sector.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.