Narrative:

I had been on position for around 40 minutes and noticed that there was a growing number of arrivals coming in the next 10 minutes. I asked the radar controller in charge if I could have a coordinator and it was mentioned that the position was going to be split. The aircraft began calling my frequency as the decombining of the position took place.prior to the decombining of the position aircraft X was on a vector of 160 degrees and at 3;100 feet to parallel the final approach course at xna for inbounds. I attempted to give the briefing to the new west controller and in the process gave a heading of 150 and a climb to 3;400 feet to aircraft X. This was to parallel the final approach course at fyv and to climb for the minimum vectoring altitude (MVA). This was to prepare the aircraft to follow aircraft Y; at this time 15 miles south east of fyv.in the coordination to decombine the position I said that I was keeping and then I said I was giving aircraft X to the west controller. During this time there was a couple of individuals that called and the information may not have been heard well. Later; I cleared aircraft Y for a visual approach. I then transferred aircraft X and he read back the frequency.the main focus of my attention was an inbound of 3 regional jets to xna and trying to coordinate with the west controller how they wanted the sequence worked out. I transferred aircraft Y to tower. I gave a traffic position to aircraft X even though I had switched him earlier and did not get a response. I thought that he had taken the radio switch. Later; I noticed that aircraft X was based closely to aircraft Y. Since I had transferred the aircraft and didn't get a response from him I thought the aircraft was turned by the west controller.after listening to the replay; I noticed that the west controller tried to point the airport out to the aircraft with no reply. So they thought I was talking to the aircraft and had turned him to follow aircraft Y. Aircraft X turned towards the airport without a clearance from ATC.when decombining the position; do so at least 5 minutes prior to the bulk of the traffic reaches the airspace. Decombining the position in this scenario was not a help to me as the controller; but an increase of my workload as I had to coordinate with the relieving controller and tried to set up a plan to set them up for success. Though we have procedures in place for decombining sectors they don't work well for each scenario and each controller likes to work things differently. I did not have a chance to discuss with the new west controller how they wanted to work the traffic which created an extra work load on my brain to assist them with their arrivals.

Related reports:

Google
 

Original NASA ASRS Text

Title: A Controller reported that while de-combining previously combined sectors he observed an aircraft assigned a downwind heading turn base leg on its own into confliction with traffic straight in to the runway.

Narrative: I had been on position for around 40 minutes and noticed that there was a growing number of arrivals coming in the next 10 minutes. I asked the Radar Controller in Charge if I could have a coordinator and it was mentioned that the position was going to be split. The aircraft began calling my frequency as the decombining of the position took place.Prior to the decombining of the position aircraft X was on a vector of 160 degrees and at 3;100 feet to parallel the final approach course at XNA for inbounds. I attempted to give the briefing to the new West Controller and in the process gave a heading of 150 and a climb to 3;400 feet to aircraft X. This was to parallel the final approach course at FYV and to climb for the Minimum Vectoring Altitude (MVA). This was to prepare the aircraft to follow Aircraft Y; at this time 15 miles south east of FYV.In the coordination to decombine the position I said that I was keeping and then I said I was giving aircraft X to the West controller. During this time there was a couple of individuals that called and the information may not have been heard well. Later; I cleared aircraft Y for a Visual Approach. I then transferred aircraft X and he read back the frequency.The main focus of my attention was an inbound of 3 regional jets to XNA and trying to coordinate with the West Controller how they wanted the sequence worked out. I transferred aircraft Y to Tower. I gave a traffic position to aircraft X even though I had switched him earlier and did not get a response. I thought that he had taken the radio switch. Later; I noticed that aircraft X was based closely to aircraft Y. Since I had transferred the aircraft and didn't get a response from him I thought the aircraft was turned by the West Controller.After listening to the replay; I noticed that the West Controller tried to point the airport out to the aircraft with no reply. So they thought I was talking to the aircraft and had turned him to follow aircraft Y. Aircraft X turned towards the airport without a clearance from ATC.When decombining the position; do so at least 5 minutes prior to the bulk of the traffic reaches the airspace. Decombining the position in this scenario was not a help to me as the controller; but an increase of my workload as I had to coordinate with the relieving controller and tried to set up a plan to set them up for success. Though we have procedures in place for decombining sectors they don't work well for each scenario and each controller likes to work things differently. I did not have a chance to discuss with the new West Controller how they wanted to work the traffic which created an extra work load on my brain to assist them with their arrivals.

Data retrieved from NASA's ASRS site 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.