Narrative:

Cpr (sjc-ict) FL410 descending into ict. Air carrier B757 (msp-gag-bgd-tcc-abq-phx) FL310, 40 mi southwest scn direct gag. Crossing path of cpr. Conflict alert activated when cpr was descending from FL350. Cpr was instructed to maintain FL330. He responded that he would descend below FL330 before he could start to climb. Separation was lost at that time and the error occurred. I felt a number of things happened to contribute to the error. 1) a line of thunderstorms forced traffic into sector creating a complex traffic situation. 2) inexperienced assistant controller. 3) noise level immediate area. 4) no history on sector that evening. 5) poor lighting in area -- had to struggle to see keyboard. Solution: draw your own conclusion.

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Original NASA ASRS Text

Title: ARTCC CTLR FAILED TO MAINTAIN LEGAL SEPARATION WITH A CESSNA CITATION DSNDING FROM FL350 AND XING THE FLT PATH OF A B737 AT FL310.

Narrative: CPR (SJC-ICT) FL410 DSNDING INTO ICT. ACR B757 (MSP-GAG-BGD-TCC-ABQ-PHX) FL310, 40 MI SW SCN DIRECT GAG. XING PATH OF CPR. CONFLICT ALERT ACTIVATED WHEN CPR WAS DSNDING FROM FL350. CPR WAS INSTRUCTED TO MAINTAIN FL330. HE RESPONDED THAT HE WOULD DSND BELOW FL330 BEFORE HE COULD START TO CLB. SEPARATION WAS LOST AT THAT TIME AND THE ERROR OCCURRED. I FELT A NUMBER OF THINGS HAPPENED TO CONTRIBUTE TO THE ERROR. 1) A LINE OF TSTMS FORCED TFC INTO SECTOR CREATING A COMPLEX TFC SIT. 2) INEXPERIENCED ASSISTANT CTLR. 3) NOISE LEVEL IMMEDIATE AREA. 4) NO HISTORY ON SECTOR THAT EVENING. 5) POOR LIGHTING IN AREA -- HAD TO STRUGGLE TO SEE KEYBOARD. SOLUTION: DRAW YOUR OWN CONCLUSION.

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.