Narrative:

ARTS IIIE system in use at S46. The inability of ARTS to identify a problem with duplicate flight numbers resulted in a loss of separation. Flight departed olm airport, IFR to boeing field. A different aircraft with the same flight number had an ARTS tag associated with a radar target at a different radar position. As a result, an ARTS data tag did not acquire on the olm departing aircraft #1. Due to position complexity and traffic volume, the radar target was not idented until loss of separation occurred. I considered traffic at the satellite 'north' position to be heavy in density, and extremely difficult in complexity for the better part of an hour. Low ceilings made IFR flight a necessity. Additionally, operation was in progress at tcm AFB. Numerous flts with foreign pilots who spoke broken english on bad radios were a major distraction. There was also a military C130 needing special assistance at grf airfield due to a nose gear problem. To put it succinctly, at times like this, we count on our equipment (ARTS in this case) to help us do our job. Had an ARTS data tag acquired on the radar target, separation would have never been lost.

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Original NASA ASRS Text

Title: ARTS TAG ON IFR DEP OFF OLM DID NOT ACQUIRE AND WAS NOT NOTICED BY CTLR. TARGET CONFLICTED WITH ANOTHER ACFT RESULTING IN AN OPERROR.

Narrative: ARTS IIIE SYS IN USE AT S46. THE INABILITY OF ARTS TO IDENT A PROB WITH DUPLICATE FLT NUMBERS RESULTED IN A LOSS OF SEPARATION. FLT DEPARTED OLM ARPT, IFR TO BOEING FIELD. A DIFFERENT ACFT WITH THE SAME FLT NUMBER HAD AN ARTS TAG ASSOCIATED WITH A RADAR TARGET AT A DIFFERENT RADAR POS. AS A RESULT, AN ARTS DATA TAG DID NOT ACQUIRE ON THE OLM DEPARTING ACFT #1. DUE TO POS COMPLEXITY AND TFC VOLUME, THE RADAR TARGET WAS NOT IDENTED UNTIL LOSS OF SEPARATION OCCURRED. I CONSIDERED TFC AT THE SATELLITE 'N' POS TO BE HEAVY IN DENSITY, AND EXTREMELY DIFFICULT IN COMPLEXITY FOR THE BETTER PART OF AN HR. LOW CEILINGS MADE IFR FLT A NECESSITY. ADDITIONALLY, OP WAS IN PROGRESS AT TCM AFB. NUMEROUS FLTS WITH FOREIGN PLTS WHO SPOKE BROKEN ENGLISH ON BAD RADIOS WERE A MAJOR DISTR. THERE WAS ALSO A MIL C130 NEEDING SPECIAL ASSISTANCE AT GRF AIRFIELD DUE TO A NOSE GEAR PROB. TO PUT IT SUCCINCTLY, AT TIMES LIKE THIS, WE COUNT ON OUR EQUIP (ARTS IN THIS CASE) TO HELP US DO OUR JOB. HAD AN ARTS DATA TAG ACQUIRED ON THE RADAR TARGET, SEPARATION WOULD HAVE NEVER BEEN LOST.

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.