Narrative:

I was working satellite sector; configuration 3; with normal traffic. Cpc working flight data notified me that ZZZ was requesting release off runway 35L for a C421 and that they would provide visual with the traffic inbound. She asked if I would like her to get the release from last. I said yes and released. So; she got the coordination; and I assumed she also released the aircraft. After the incoming traffic had landed with no sign of the C421 departing; she came over and clarified that she had not released the aircraft; only had gotten release with last. I immediately called ZZZ and released the aircraft. At the time I had another IFR aircraft inbound to ZZZ about 15 miles south of the airport. Once the C421 departed and assigned 9;000 MSL; I cleared the BE30 for the visual approach. As the C421 was climbing; I realized that separation might be lost. I called traffic. Neither aircraft saw the other. I ended up canceling the approach clearance of the BE30 and turning him westbound; but separation was lost. There were several options that I did not take that would have prevented this occurrence. 1. Do not assume!! Verify which coordination was completed. 2. Call ZZZ tower for visual separation; as the aircraft were within seven miles of the airport 3. Wait until the BE30 was within range of the airport before releasing the C421. 4. Leave it alone because it would have worked. It was actually after I canceled the approach clearance and climbed the aircraft that I lost separation.

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Original NASA ASRS Text

Title: A TRACON Controller described a loss of separation event between an IFR arrival and departure complicated by failed internal coordination regarding a release and an intervention vector that did not provide adequate spacing.

Narrative: I was working Satellite sector; configuration 3; with normal traffic. CPC working Flight Data notified me that ZZZ was requesting release off Runway 35L for a C421 and that they would provide visual with the traffic inbound. She asked if I would like her to get the release from LAST. I said yes and released. So; she got the coordination; and I assumed she also released the aircraft. After the incoming traffic had landed with no sign of the C421 departing; she came over and clarified that she had not released the aircraft; only had gotten release with LAST. I immediately called ZZZ and released the aircraft. At the time I had another IFR aircraft inbound to ZZZ about 15 miles south of the airport. Once the C421 departed and assigned 9;000 MSL; I cleared the BE30 for the Visual Approach. As the C421 was climbing; I realized that separation might be lost. I called traffic. Neither aircraft saw the other. I ended up canceling the approach clearance of the BE30 and turning him westbound; but separation was lost. There were several options that I did not take that would have prevented this occurrence. 1. Do not assume!! Verify which coordination was completed. 2. Call ZZZ Tower for Visual Separation; as the aircraft were within seven miles of the airport 3. Wait until the BE30 was within range of the airport before releasing the C421. 4. Leave it alone because it would have worked. It was actually after I canceled the approach clearance and climbed the aircraft that I lost separation.

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.