Narrative:

Aircraft Y had been given a crossing and switched to another sector. Aircraft X was at FL270 flying under aircraft Y. Situational awareness was not maintained because I had made a judgement that aircraft Y would be under aircraft X when they passed. Aircraft Y should have been descended and not switched to the next controller until separation had been established. A loss of concentration and awareness of where the 2 aircraft crossed were major factors in this error. Aircraft X TCASII alerted the controller, but within 5 seconds separation was lost. I felt there was no need to turn aircraft X in an excessive manner because the separation was already lost. Passenger were a factor and I knew they (planes) would not be too close to compromise safety, so I only turned aircraft X 20 degrees.

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Original NASA ASRS Text

Title: RPTR DID NOT ENSURE STANDARD SEPARATION EXISTED BTWN ACFT X AND ACFT Y BEFORE ACFT Y WAS GIVEN A FREQ CHANGE.

Narrative: ACFT Y HAD BEEN GIVEN A XING AND SWITCHED TO ANOTHER SECTOR. ACFT X WAS AT FL270 FLYING UNDER ACFT Y. SITUATIONAL AWARENESS WAS NOT MAINTAINED BECAUSE I HAD MADE A JUDGEMENT THAT ACFT Y WOULD BE UNDER ACFT X WHEN THEY PASSED. ACFT Y SHOULD HAVE BEEN DSNDED AND NOT SWITCHED TO THE NEXT CTLR UNTIL SEPARATION HAD BEEN ESTABLISHED. A LOSS OF CONCENTRATION AND AWARENESS OF WHERE THE 2 ACFT CROSSED WERE MAJOR FACTORS IN THIS ERROR. ACFT X TCASII ALERTED THE CTLR, BUT WITHIN 5 SECONDS SEPARATION WAS LOST. I FELT THERE WAS NO NEED TO TURN ACFT X IN AN EXCESSIVE MANNER BECAUSE THE SEPARATION WAS ALREADY LOST. PAX WERE A FACTOR AND I KNEW THEY (PLANES) WOULD NOT BE TOO CLOSE TO COMPROMISE SAFETY, SO I ONLY TURNED ACFT X 20 DEGS.

Data retrieved from NASA's ASRS site as of July 2007 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.