Narrative:

I inadvertently clrd medium large transport X to filed altitude of FL350 instead of the top of my altitude stratum, FL230. I handed off medium large transport X to high altitude sector 91 and worked on 2 other sep problems and talked to several other aircraft. Seeing that medium large transport X was climbing out of FL240, I believed that I must have changed it to high altitude's frequency, and then dropped the data block on medium large transport X. Medium large transport X called approximately 5-10 mins later advising he was level at FL350. Believing medium large transport X came back to my frequency by mistake, I changed him to high altitude's frequency. I later found out that sep was lost between medium large transport X and an large transport Y at FL330, and also by listening to the tapes that I had clrd medium large transport X to FL350. Aircraft did not take evasive action, but ultra-high controller turned the large transport Y away from medium large transport X. Closest proximity was about 3.9 NM and 900' at 33900'. Supplemental information from acn 80593: when we were told about the altitude alert, I saw the traffic before he told us. It seems the departure controller wrote down FL230 but said FL350. Then, to make matters worse, he forgot to hand us off. Supplemental information from acn 80699: at 34500' the first officer spotted an eastbound and I became suspicious of a problem and told the controller that we were leveling '350,' did he still want us on this frequency. He told us to switch to 135.15. At this time we were informed of the quality assurance alert. The 2 problems were the controller not following established procedures and the captain not doublechking when an unusual clearance was received.

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Original NASA ASRS Text

Title: ARTCC CTLR CLIMBED AN MLG ABOVE HIS SECTOR ALT LIMITS WITHOUT COORD OR HANDOFF AND CREATED LESS THAN STANDARD SEPARATION WITH AN LGT.

Narrative: I INADVERTENTLY CLRD MLG X TO FILED ALT OF FL350 INSTEAD OF THE TOP OF MY ALT STRATUM, FL230. I HANDED OFF MLG X TO HIGH ALT SECTOR 91 AND WORKED ON 2 OTHER SEP PROBS AND TALKED TO SEVERAL OTHER ACFT. SEEING THAT MLG X WAS CLBING OUT OF FL240, I BELIEVED THAT I MUST HAVE CHANGED IT TO HIGH ALT'S FREQ, AND THEN DROPPED THE DATA BLOCK ON MLG X. MLG X CALLED APPROX 5-10 MINS LATER ADVISING HE WAS LEVEL AT FL350. BELIEVING MLG X CAME BACK TO MY FREQ BY MISTAKE, I CHANGED HIM TO HIGH ALT'S FREQ. I LATER FOUND OUT THAT SEP WAS LOST BTWN MLG X AND AN LGT Y AT FL330, AND ALSO BY LISTENING TO THE TAPES THAT I HAD CLRD MLG X TO FL350. ACFT DID NOT TAKE EVASIVE ACTION, BUT ULTRA-HIGH CTLR TURNED THE LGT Y AWAY FROM MLG X. CLOSEST PROX WAS ABOUT 3.9 NM AND 900' AT 33900'. SUPPLEMENTAL INFORMATION FROM ACN 80593: WHEN WE WERE TOLD ABOUT THE ALT ALERT, I SAW THE TFC BEFORE HE TOLD US. IT SEEMS THE DEP CTLR WROTE DOWN FL230 BUT SAID FL350. THEN, TO MAKE MATTERS WORSE, HE FORGOT TO HAND US OFF. SUPPLEMENTAL INFO FROM ACN 80699: AT 34500' THE F/O SPOTTED AN EBND AND I BECAME SUSPICIOUS OF A PROB AND TOLD THE CTLR THAT WE WERE LEVELING '350,' DID HE STILL WANT US ON THIS FREQ. HE TOLD US TO SWITCH TO 135.15. AT THIS TIME WE WERE INFORMED OF THE QUALITY ASSURANCE ALERT. THE 2 PROBS WERE THE CTLR NOT FOLLOWING ESTABLISHED PROCS AND THE CAPT NOT DOUBLECHKING WHEN AN UNUSUAL CLRNC WAS RECEIVED.

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.