Narrative:

Took radar handoff on aircraft #1. Aircraft #1 was a departure from adjacent center. Since it was a departure, our LOA indicates those aircraft will be climbing to FL260. Adjacent center called me after I had the handoff, that aircraft #1 was climbing to FL310. I approved it, since aircraft #1 was requesting FL390. Aircraft #2 was in level flight, opposite direction at FL330. I was concerned about getting aircraft #1 up to requested altitude because there was another aircraft at FL310, same direction as aircraft #1, behind aircraft #1. I did not have the handoff on that aircraft yet, so I couldn't tell how fast it was in relation to aircraft #1. I did a traffic search in my sector where most of the conflictions take place for aircraft 1's route of flight. I failed to observe aircraft #2's relative position. I assigned aircraft #1 FL390 and immediately notice another aircraft close to my boundary that was head on with 2 other airplanes I was working. I called that sector and asked what was going on with said aircraft. Controller said he was not yet in communications with aircraft and he didn't know why that aircraft was off his course. I then turned 1 of the 2 aircraft away from the intruder aircraft. Right after that, my d-side (manual controller) alerted me to the head-on situation between aircraft #1 and aircraft #2. At that point they were less than 10 mi apart and aircraft #1 mode C indicated FL317. I told aircraft #1 to 'descend and maintain FL290, expedite descent, TA 12 O'clock, 5 mi, FL330.' I then told aircraft #2 'TA, traffic 12 O'clock, 1 mi, FL317 descending.' I next told aircraft #1 to report leaving FL310. This happened so quick (since it was head- on). My mileage given in traffic calls was probably not precise, but at less than 10 mi head-on, it's impossible to tell. I should have told afct #1 to 'descend immediately' as per 7110.65 ATP. Also, it should have been 'safety' alert, not TA. Aircraft #1 was a cpr jet, no TCASII. Aircraft #2 was a foreign carrier, so I do not believe it had TCASII either. This situation was traumatic for me and only reinforces my belief that 2 sets of eyes are better than 1. I hope the FAA will quit being so concerned with how much it costs to get adequate staffing. I am so lucky I had an alert d-side plugged in with me. If he hadn't, those 2 aircraft might have been a lot closer than 1300 ft. Also, the conflict alert function never activated. Contributing factor that I didn't catch my mistake was adjacent facility's deviating aircraft that consumed my attention.

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Original NASA ASRS Text

Title: ARTCC RADAR CTLR CLBED A CPR JET THROUGH AN ALT OCCUPIED BY AN ACR JET. THE ARTCC D CTLR SAW THE POTENTIAL CONFLICT LTSS ABOUT TO OCCUR AND WARNED THE RADAR CTLR. THE RADAR CTLR DSNDED THE CPR JET AND GAVE BOTH ACFT TA'S AND STANDARD SEPARATION WAS LOST. THE CONFLICT ALERT DID NOT ACTIVATE AND RPTR INDICATES THAT APPARENTLY NEITHER ACFT INVOLVED HAD TCASII.

Narrative: TOOK RADAR HDOF ON ACFT #1. ACFT #1 WAS A DEP FROM ADJACENT CTR. SINCE IT WAS A DEP, OUR LOA INDICATES THOSE ACFT WILL BE CLBING TO FL260. ADJACENT CTR CALLED ME AFTER I HAD THE HDOF, THAT ACFT #1 WAS CLBING TO FL310. I APPROVED IT, SINCE ACFT #1 WAS REQUESTING FL390. ACFT #2 WAS IN LEVEL FLT, OPPOSITE DIRECTION AT FL330. I WAS CONCERNED ABOUT GETTING ACFT #1 UP TO REQUESTED ALT BECAUSE THERE WAS ANOTHER ACFT AT FL310, SAME DIRECTION AS ACFT #1, BEHIND ACFT #1. I DID NOT HAVE THE HDOF ON THAT ACFT YET, SO I COULDN'T TELL HOW FAST IT WAS IN RELATION TO ACFT #1. I DID A TFC SEARCH IN MY SECTOR WHERE MOST OF THE CONFLICTIONS TAKE PLACE FOR ACFT 1'S RTE OF FLT. I FAILED TO OBSERVE ACFT #2'S RELATIVE POS. I ASSIGNED ACFT #1 FL390 AND IMMEDIATELY NOTICE ANOTHER ACFT CLOSE TO MY BOUNDARY THAT WAS HEAD ON WITH 2 OTHER AIRPLANES I WAS WORKING. I CALLED THAT SECTOR AND ASKED WHAT WAS GOING ON WITH SAID ACFT. CTLR SAID HE WAS NOT YET IN COMS WITH ACFT AND HE DIDN'T KNOW WHY THAT ACFT WAS OFF HIS COURSE. I THEN TURNED 1 OF THE 2 ACFT AWAY FROM THE INTRUDER ACFT. RIGHT AFTER THAT, MY D-SIDE (MANUAL CTLR) ALERTED ME TO THE HEAD-ON SIT BTWN ACFT #1 AND ACFT #2. AT THAT POINT THEY WERE LESS THAN 10 MI APART AND ACFT #1 MODE C INDICATED FL317. I TOLD ACFT #1 TO 'DSND AND MAINTAIN FL290, EXPEDITE DSCNT, TA 12 O'CLOCK, 5 MI, FL330.' I THEN TOLD ACFT #2 'TA, TFC 12 O'CLOCK, 1 MI, FL317 DSNDING.' I NEXT TOLD ACFT #1 TO RPT LEAVING FL310. THIS HAPPENED SO QUICK (SINCE IT WAS HEAD- ON). MY MILEAGE GIVEN IN TFC CALLS WAS PROBABLY NOT PRECISE, BUT AT LESS THAN 10 MI HEAD-ON, IT'S IMPOSSIBLE TO TELL. I SHOULD HAVE TOLD AFCT #1 TO 'DSND IMMEDIATELY' AS PER 7110.65 ATP. ALSO, IT SHOULD HAVE BEEN 'SAFETY' ALERT, NOT TA. ACFT #1 WAS A CPR JET, NO TCASII. ACFT #2 WAS A FOREIGN CARRIER, SO I DO NOT BELIEVE IT HAD TCASII EITHER. THIS SIT WAS TRAUMATIC FOR ME AND ONLY REINFORCES MY BELIEF THAT 2 SETS OF EYES ARE BETTER THAN 1. I HOPE THE FAA WILL QUIT BEING SO CONCERNED WITH HOW MUCH IT COSTS TO GET ADEQUATE STAFFING. I AM SO LUCKY I HAD AN ALERT D-SIDE PLUGGED IN WITH ME. IF HE HADN'T, THOSE 2 ACFT MIGHT HAVE BEEN A LOT CLOSER THAN 1300 FT. ALSO, THE CONFLICT ALERT FUNCTION NEVER ACTIVATED. CONTRIBUTING FACTOR THAT I DIDN'T CATCH MY MISTAKE WAS ADJACENT FACILITY'S DEVIATING ACFT THAT CONSUMED MY ATTN.

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.