Narrative:

I was working north local at ord airport on mar/sun/93 and the runway 27R final was tight with approximately 10 aircraft. Although the WX was reported as IFR and the RVR equipment was issuing rptable values, the visibility on the runway 27R final was adequate for me to use visual separation between these aircraft. Approximately 10 days after this occurred the staff at ord informed me I was involved in an operational error. They did not interview me until apr/xx/93 although the NTSB did on approximately mar/xx/93, but they never asked me any question about separation. Although the aircraft involved did not have radar separation I was under the impression that I could use visual if I met the requirements in the 7110.65.

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Original NASA ASRS Text

Title: A LCL CTLR WAS USING VISUAL SEPARATION BTWN ARRIVING ACFT WHEN THE WX WAS BELOW BASIC VFR MINIMUMS.

Narrative: I WAS WORKING N LCL AT ORD ARPT ON MAR/SUN/93 AND THE RWY 27R FINAL WAS TIGHT WITH APPROX 10 ACFT. ALTHOUGH THE WX WAS RPTED AS IFR AND THE RVR EQUIP WAS ISSUING RPTABLE VALUES, THE VISIBILITY ON THE RWY 27R FINAL WAS ADEQUATE FOR ME TO USE VISUAL SEPARATION BTWN THESE ACFT. APPROX 10 DAYS AFTER THIS OCCURRED THE STAFF AT ORD INFORMED ME I WAS INVOLVED IN AN OPERROR. THEY DID NOT INTERVIEW ME UNTIL APR/XX/93 ALTHOUGH THE NTSB DID ON APPROX MAR/XX/93, BUT THEY NEVER ASKED ME ANY QUESTION ABOUT SEPARATION. ALTHOUGH THE ACFT INVOLVED DID NOT HAVE RADAR SEPARATION I WAS UNDER THE IMPRESSION THAT I COULD USE VISUAL IF I MET THE REQUIREMENTS IN THE 7110.65.

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.