Narrative:

Air carrier X departed den J17 publication J28 gck. X was climbed to FL330 and handed off to sector 30. Sector 30 took the handoff and then handed X to sector 39. X was stopped at FL330 at this time. Prior to accepting the handoff on X sector 39 had handed air carrier Y (a wbound overflt level at FL350) off to sector 30 and shipped communications to sector 30. Sector 29 transferred communications on X to sector 39 (as per sector operating procedures). Sector 30 realized that if climbed to FL370, X would conflict with Y southeast of publication. X checked in on sector 39's frequency and was told to expect higher in 4 mins (this occurred at 39:56 on the accompanying map). Air carrier Y proceeded wbound and sector 39 controller dropped Y's data block from sector 39's radar scope. Air carrier X was then cleared to FL370 through air carrier Y. Sep was 1.8 mi and 1500'. The C/a went off at the same time the sector 30 controller was asking the sector 39 controller if she had climbed X. X was then turned to 50 degrees and descended, but due to the proximity of his traffic, sep was lost as soon as the clearance was acknowledged. The aircraft were by each other before the corrective action took place. Sector operating procedures or logic? It was the understanding of the sector 30 controller that sector 39 did have control for climb on contact of air carrier X, but X had been stopped at FL330 for air carrier Y. Sector 30 did not coordinate this since Y was still in sector 39's airspace when sector 39 had control and communication with X. When the error occurred at 44:54 (on the map) air carrier Y was more than 2 1/2 mi outside sector 39's airspace and it was established that sector 39 did not have to legally watch him anymore. Suggestion: closer coordination has been established between sector 30 and sector 39, especially on situations like the above. Supplemental information from acn 100345: we were level at FL330. As we approached publication and had started a left turn to intercept J28, ZDV cleared us to climb to FL370. In a climbing left turn we saw another plane wbound, and I stopped our climb at about 34300' until we were clear of that plane. I then continued to climb and at about 35500' ZDV told us to 'descend now to FL330 and turn left to 050 degree heading.' we explained that we saw the other plane and that we were clear of it, but the center emphatically repeated the clearance, so I immediately went to idle thrust, full speed brakes and started a descending left turn. (My thought was that there may be another plane nearby that we hadn't seen.) a short time later a different controller cleared us on course and to FL370. The controller stated that there was only 1 other plane involved. The center was very busy at the time of this occurrence.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN 2 ACR. OPERATIONAL ERROR.

Narrative: ACR X DEPARTED DEN J17 PUB J28 GCK. X WAS CLBED TO FL330 AND HANDED OFF TO SECTOR 30. SECTOR 30 TOOK THE HDOF AND THEN HANDED X TO SECTOR 39. X WAS STOPPED AT FL330 AT THIS TIME. PRIOR TO ACCEPTING THE HDOF ON X SECTOR 39 HAD HANDED ACR Y (A WBOUND OVERFLT LEVEL AT FL350) OFF TO SECTOR 30 AND SHIPPED COMS TO SECTOR 30. SECTOR 29 TRANSFERRED COMS ON X TO SECTOR 39 (AS PER SECTOR OPERATING PROCS). SECTOR 30 REALIZED THAT IF CLBED TO FL370, X WOULD CONFLICT WITH Y SE OF PUB. X CHKED IN ON SECTOR 39'S FREQ AND WAS TOLD TO EXPECT HIGHER IN 4 MINS (THIS OCCURRED AT 39:56 ON THE ACCOMPANYING MAP). ACR Y PROCEEDED WBOUND AND SECTOR 39 CTLR DROPPED Y'S DATA BLOCK FROM SECTOR 39'S RADAR SCOPE. ACR X WAS THEN CLRED TO FL370 THROUGH ACR Y. SEP WAS 1.8 MI AND 1500'. THE C/A WENT OFF AT THE SAME TIME THE SECTOR 30 CTLR WAS ASKING THE SECTOR 39 CTLR IF SHE HAD CLBED X. X WAS THEN TURNED TO 50 DEGS AND DSNDED, BUT DUE TO THE PROX OF HIS TFC, SEP WAS LOST AS SOON AS THE CLRNC WAS ACKNOWLEDGED. THE ACFT WERE BY EACH OTHER BEFORE THE CORRECTIVE ACTION TOOK PLACE. SECTOR OPERATING PROCS OR LOGIC? IT WAS THE UNDERSTANDING OF THE SECTOR 30 CTLR THAT SECTOR 39 DID HAVE CTL FOR CLB ON CONTACT OF ACR X, BUT X HAD BEEN STOPPED AT FL330 FOR ACR Y. SECTOR 30 DID NOT COORDINATE THIS SINCE Y WAS STILL IN SECTOR 39'S AIRSPACE WHEN SECTOR 39 HAD CTL AND COM WITH X. WHEN THE ERROR OCCURRED AT 44:54 (ON THE MAP) ACR Y WAS MORE THAN 2 1/2 MI OUTSIDE SECTOR 39'S AIRSPACE AND IT WAS ESTABLISHED THAT SECTOR 39 DID NOT HAVE TO LEGALLY WATCH HIM ANYMORE. SUGGESTION: CLOSER COORD HAS BEEN ESTABLISHED BTWN SECTOR 30 AND SECTOR 39, ESPECIALLY ON SITUATIONS LIKE THE ABOVE. SUPPLEMENTAL INFO FROM ACN 100345: WE WERE LEVEL AT FL330. AS WE APCHED PUB AND HAD STARTED A LEFT TURN TO INTERCEPT J28, ZDV CLRED US TO CLB TO FL370. IN A CLBING LEFT TURN WE SAW ANOTHER PLANE WBOUND, AND I STOPPED OUR CLB AT ABOUT 34300' UNTIL WE WERE CLR OF THAT PLANE. I THEN CONTINUED TO CLB AND AT ABOUT 35500' ZDV TOLD US TO 'DSND NOW TO FL330 AND TURN LEFT TO 050 DEG HDG.' WE EXPLAINED THAT WE SAW THE OTHER PLANE AND THAT WE WERE CLR OF IT, BUT THE CENTER EMPHATICALLY REPEATED THE CLRNC, SO I IMMEDIATELY WENT TO IDLE THRUST, FULL SPEED BRAKES AND STARTED A DSNDING LEFT TURN. (MY THOUGHT WAS THAT THERE MAY BE ANOTHER PLANE NEARBY THAT WE HADN'T SEEN.) A SHORT TIME LATER A DIFFERENT CTLR CLRED US ON COURSE AND TO FL370. THE CTLR STATED THAT THERE WAS ONLY 1 OTHER PLANE INVOLVED. THE CENTER WAS VERY BUSY AT THE TIME OF THIS OCCURRENCE.

Data retrieved from NASA's ASRS site as of August 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.