Narrative:

Climbing out of portland, or, heading eastbound. FK28 inbound portland from the east. DC8 checked on climbing to FL230 and I climbed him to FL330 expecting to top FK28 who was at FL240. I asked DC8 for best rate of climb through FL250. When I noticed that these 2 aircraft may get close, I attempted to put a halo (5 mi ring) around DC8. The host system sees this input as a low priority, therefore, the halo did not display soon enough to visualize how close these aircraft may get. Attempted corrective action with turns, but separation was lost. Had the halo been immediate, I could have stopped the FK28 below DC8 preventing separation loss. Supplemental information from acn 442164: I was working R34. Had DC8 climbing off portland eastbound. I shipped DC8 to sector 16. Shortly after that, FK28 checked on my frequency. Later, sector 16 called and asked if I would start descending FK28. I assessed the traffic situation and thought it wouldn't work if I started FK28 down. I called sector 16 back and asked if he was trying to top FK28 with DC8. After our conversation, I thought sector 16 wasn't going to try to top FK28, and they would let DC8 level at FL230. I observed DC8 climbing through FL233 so I turned FK28 to 250 degrees. After they passed, I turned FK28 back to portland. I feel this operational error occurred because of poor coordination between myself and sector 16. It could have been avoided by using correct phraseology in our coordination.

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Original NASA ASRS Text

Title: ACFT X WAS GIVEN A CLRNC BY CTL 1 TO CLB ABOVE ACFT Y. SEPARATION WAS LOST, RESULTING IN AN OPERROR.

Narrative: CLBING OUT OF PORTLAND, OR, HDG EBOUND. FK28 INBOUND PORTLAND FROM THE E. DC8 CHKED ON CLBING TO FL230 AND I CLBED HIM TO FL330 EXPECTING TO TOP FK28 WHO WAS AT FL240. I ASKED DC8 FOR BEST RATE OF CLB THROUGH FL250. WHEN I NOTICED THAT THESE 2 ACFT MAY GET CLOSE, I ATTEMPTED TO PUT A HALO (5 MI RING) AROUND DC8. THE HOST SYS SEES THIS INPUT AS A LOW PRIORITY, THEREFORE, THE HALO DID NOT DISPLAY SOON ENOUGH TO VISUALIZE HOW CLOSE THESE ACFT MAY GET. ATTEMPTED CORRECTIVE ACTION WITH TURNS, BUT SEPARATION WAS LOST. HAD THE HALO BEEN IMMEDIATE, I COULD HAVE STOPPED THE FK28 BELOW DC8 PREVENTING SEPARATION LOSS. SUPPLEMENTAL INFO FROM ACN 442164: I WAS WORKING R34. HAD DC8 CLBING OFF PORTLAND EBOUND. I SHIPPED DC8 TO SECTOR 16. SHORTLY AFTER THAT, FK28 CHKED ON MY FREQ. LATER, SECTOR 16 CALLED AND ASKED IF I WOULD START DSNDING FK28. I ASSESSED THE TFC SIT AND THOUGHT IT WOULDN'T WORK IF I STARTED FK28 DOWN. I CALLED SECTOR 16 BACK AND ASKED IF HE WAS TRYING TO TOP FK28 WITH DC8. AFTER OUR CONVERSATION, I THOUGHT SECTOR 16 WASN'T GOING TO TRY TO TOP FK28, AND THEY WOULD LET DC8 LEVEL AT FL230. I OBSERVED DC8 CLBING THROUGH FL233 SO I TURNED FK28 TO 250 DEGS. AFTER THEY PASSED, I TURNED FK28 BACK TO PORTLAND. I FEEL THIS OPERROR OCCURRED BECAUSE OF POOR COORD BTWN MYSELF AND SECTOR 16. IT COULD HAVE BEEN AVOIDED BY USING CORRECT PHRASEOLOGY IN OUR COORD.

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.