Narrative:

I was d-side for sector xx and xy which were combined. I had just returned from a break. Weather in the sector was MVFR; with visual approaches to ZZZ in the south and IFR and ILS/GPS approaches at ZZZ1 in the north. Traffic was moderate to heavy and complex with several arrivals of various types to ZZZ and ZZZ1; flight following; practice approaches; sky diving activity; and arrival and departure traffic from the area. There was sequencing into ZZZ1. Number 1 was a SW2; number two was a C182; and number 3 was a GLF4. ZZZ1 tower requested an syd release with C182 for a CL30 opposite direction to the arrivals. The GLF4 was 20 plus miles in trail and not yet cleared for the approach. Due to its position and the fact it was just flying from ZZZ to ZZZ1; I assumed it was a slow aircraft. I approved syd and issued the departure a 180 heading to provide lateral spacing from the GLF4; because I thought the GLF4 was slow and they would pass 10 plus miles south of the field. I don't specifically recall what I told the r-side; I think I said 'syd ZZZ1.' I dm'ed the aircraft; started a track; entered H180 in the 4th line; and entered a temporary altitude of 080. The r-side thought I went syd with the GLF4. Both the r-side and I were saturated with other tasks and did not recognize the situation until the GLF4 was already cleared for the approach; established inbound; and descending. Once the r-side recognized the situation; he asked who I went syd with. When I told him it was the C182 he broke the GLF4 off the approach as I called the tower to see if the CL30 was rolling yet or not. The CL30 was rolling. The r-side issued the GLF4 a left 360 because terrain was lower to the west. I coordinated with ZZZ1 tower; they said they had the GLF4 in sight and were providing visual. They then asked if he was turning; I said yes; and they shipped the Cl30. As soon as the CL30 checked on; the r-side issued a further right turn. The tower then called; said they still had both aircraft in sight; and asked us to turn the GLF4 to the right; inbound; and transfer communication. It was too late by the time I could relay that to the r-side; the GLF4 was already in the left turn and separation with the CL30 was already lost. Once the problem was recognized; both the r-side and I tried to increase separation; and/or coordinate with the tower to provide visual separation. The r-side continued working to increase separation after it was apparent that separation would be lost. In hind sight there were multiple different actions that could have been taken by both me and the r-side to have avoided the loss of separation. I have definitely learned from the experience. I did not recognize the GLF4 was a jet; I did not clearly communicate to the r-side who I went syd with; and I did not notice the situation in enough time to avoid losing separation. Additionally; the work load at the sector was high; the frequency was somewhat congested; and because of that it was difficult to quickly and clearly relay information to the r-side regarding the tower maintaining visual separation. Recommendation; to prevent this from occurring again; whenever I use syd; especially with multiple aircraft being vectors for approaches; I will do a better job communicating with my r-side and making sure our plans are the same. I will also evaluate the types of aircraft more diligently and consider aircraft performance. I will pay special attention in my scan to the airports and airport traffic to ensure that I catch errors sooner so that corrective action can be taken in a timelier manner. Once the situation is recognized; I could have taken more assertive and aggressive action to ensure separation will be maintained. Additionally; if the sectors were split; the work load would have been substantially lower and the error could have more easily been avoided.

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Original NASA ASRS Text

Title: Enroute Controller described a loss of separation event when coordination regarding an opposite direction operation was confused between the RADAR and Data controllers.

Narrative: I was D-Side for Sector XX and XY which were combined. I had just returned from a break. Weather in the sector was MVFR; with visual approaches to ZZZ in the South and IFR and ILS/GPS approaches at ZZZ1 in the North. Traffic was moderate to heavy and complex with several arrivals of various types to ZZZ and ZZZ1; flight following; practice approaches; sky diving activity; and arrival and departure traffic from the area. There was sequencing into ZZZ1. Number 1 was a SW2; number two was a C182; and number 3 was a GLF4. ZZZ1 Tower requested an SYD release with C182 for a CL30 opposite direction to the arrivals. The GLF4 was 20 plus miles in trail and not yet cleared for the approach. Due to its position and the fact it was just flying from ZZZ to ZZZ1; I assumed it was a slow aircraft. I approved SYD and issued the departure a 180 heading to provide lateral spacing from the GLF4; because I thought the GLF4 was slow and they would pass 10 plus miles south of the field. I don't specifically recall what I told the R-Side; I think I said 'SYD ZZZ1.' I DM'ed the aircraft; started a track; entered H180 in the 4th line; and entered a temporary altitude of 080. The R-Side thought I went SYD with the GLF4. Both the R-Side and I were saturated with other tasks and did not recognize the situation until the GLF4 was already cleared for the approach; established inbound; and descending. Once the R-Side recognized the situation; he asked who I went SYD with. When I told him it was the C182 he broke the GLF4 off the approach as I called the Tower to see if the CL30 was rolling yet or not. The CL30 was rolling. The R-Side issued the GLF4 a left 360 because terrain was lower to the west. I coordinated with ZZZ1 Tower; they said they had the GLF4 in sight and were providing visual. They then asked if he was turning; I said yes; and they shipped the Cl30. As soon as the CL30 checked on; the R-Side issued a further right turn. The Tower then called; said they still had both aircraft in sight; and asked us to turn the GLF4 to the right; inbound; and transfer communication. It was too late by the time I could relay that to the R-Side; the GLF4 was already in the left turn and separation with the CL30 was already lost. Once the problem was recognized; both the R-Side and I tried to increase separation; and/or coordinate with the Tower to provide visual separation. The R-Side continued working to increase separation after it was apparent that separation would be lost. In hind sight there were multiple different actions that could have been taken by both me and the R-Side to have avoided the loss of separation. I have definitely learned from the experience. I did not recognize the GLF4 was a jet; I did not clearly communicate to the R-Side who I went SYD with; and I did not notice the situation in enough time to avoid losing separation. Additionally; the work load at the sector was high; the frequency was somewhat congested; and because of that it was difficult to quickly and clearly relay information to the R-Side regarding the Tower maintaining visual separation. Recommendation; to prevent this from occurring again; whenever I use SYD; especially with multiple aircraft being vectors for approaches; I will do a better job communicating with my R-Side and making sure our plans are the same. I will also evaluate the types of aircraft more diligently and consider aircraft performance. I will pay special attention in my scan to the airports and airport traffic to ensure that I catch errors sooner so that corrective action can be taken in a timelier manner. Once the situation is recognized; I could have taken more assertive and aggressive action to ensure separation will be maintained. Additionally; if the sectors were split; the work load would have been substantially lower and the error could have more easily been avoided.

Data retrieved from NASA's ASRS site as of July 2013 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.