Narrative:

I was watching my student air traffic controller on sector 6 in ZSE's airspace. Traffic was moderate with routine complexity. Air carrier Y was northbound at 16000 ft MSL on an IFR flight plan from mfr to sea via direct olm, OLM2 arrival. Air carrier X was on an IFR flight plan from pdx to oak via direct eug, climbing to 15000 ft MSL. My student took the handoff from pdx approach and climbed air carrier X to FL230. For some unknown reason I missed the check-on and clearance for air carrier X. The conflict alert function soon went off and I asked my student if we were talking to air carrier X. He responded by saying 'negative.' he then reclred air carrier X to maintain 15000 ft. Air carrier X responded with a comment stating he was descending back to 15000 ft. My student then turned air carrier Y 50 degrees left and received no response. I keyed up the microphone and issued air carrier X a left turn to 130 degree heading. Someone responded with 'blocked.' I reissued the left turn to air carrier X. Someone responded with 'blocked,' again. At that time the pilot of air carrier Y stated he was responding to a TCASII RA by descending. Air carrier X then responded with a TCASII RA by climbing again. Separation was lost as the targets merged. I should have caught my student's clearance to air carrier X. I was paying close attention, but still missed it. If we left the air carrier X climbing to FL230, chances are the aircraft would not have gotten as close.

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Original NASA ASRS Text

Title: ZSE CTLR PROVIDING CTLR INSTRUCTION IS UNABLE TO ESTABLISH SEPARATION DUE TO DEVELOPMENTAL ERRONEOUS CTL INSTRUCTIONS.

Narrative: I WAS WATCHING MY STUDENT AIR TFC CTLR ON SECTOR 6 IN ZSE'S AIRSPACE. TFC WAS MODERATE WITH ROUTINE COMPLEXITY. ACR Y WAS NBOUND AT 16000 FT MSL ON AN IFR FLT PLAN FROM MFR TO SEA VIA DIRECT OLM, OLM2 ARR. ACR X WAS ON AN IFR FLT PLAN FROM PDX TO OAK VIA DIRECT EUG, CLBING TO 15000 FT MSL. MY STUDENT TOOK THE HDOF FROM PDX APCH AND CLBED ACR X TO FL230. FOR SOME UNKNOWN REASON I MISSED THE CHK-ON AND CLRNC FOR ACR X. THE CONFLICT ALERT FUNCTION SOON WENT OFF AND I ASKED MY STUDENT IF WE WERE TALKING TO ACR X. HE RESPONDED BY SAYING 'NEGATIVE.' HE THEN RECLRED ACR X TO MAINTAIN 15000 FT. ACR X RESPONDED WITH A COMMENT STATING HE WAS DSNDING BACK TO 15000 FT. MY STUDENT THEN TURNED ACR Y 50 DEGS L AND RECEIVED NO RESPONSE. I KEYED UP THE MIKE AND ISSUED ACR X A L TURN TO 130 DEG HDG. SOMEONE RESPONDED WITH 'BLOCKED.' I REISSUED THE L TURN TO ACR X. SOMEONE RESPONDED WITH 'BLOCKED,' AGAIN. AT THAT TIME THE PLT OF ACR Y STATED HE WAS RESPONDING TO A TCASII RA BY DSNDING. ACR X THEN RESPONDED WITH A TCASII RA BY CLBING AGAIN. SEPARATION WAS LOST AS THE TARGETS MERGED. I SHOULD HAVE CAUGHT MY STUDENT'S CLRNC TO ACR X. I WAS PAYING CLOSE ATTN, BUT STILL MISSED IT. IF WE LEFT THE ACR X CLBING TO FL230, CHANCES ARE THE ACFT WOULD NOT HAVE GOTTEN AS CLOSE.

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.