Narrative:

I was working a high altitude center sector when I descended the C560 through the altitude of the B738. No radar alarms activated even though the proximity was very close.

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Original NASA ASRS Text

Title: ZSU CTLR EXPERIENCED OPERROR AT FL380 WHEN DSNDING ACFT THROUGH OCCUPIED ALT.

Narrative: I WAS WORKING A HIGH ALT CTR SECTOR WHEN I DSNDED THE C560 THROUGH THE ALT OF THE B738. NO RADAR ALARMS ACTIVATED EVEN THOUGH THE PROX WAS VERY CLOSE.

Data retrieved from NASA's ASRS site as of January 2009 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.