Narrative:

I was working war approach at grr. We received a manual handoff on a primary only aircraft. We have ASR-9 and have the ability to manually tag and identify primaries, which was done. There were 3 aircraft with primary/alpha numeric tracks on them, so I notified the os/ras of this fact. I issued traffic to aircraft X, worked diligently to keep his alpha numeric track on the scope, as it was having trouble staying on initially. Approximately 15 mins later, I debriefed the relieving specialist via physically pointing to 3 aircraft and 3 corresponding strips associated with each aircraft. The relieving specialist did not see the aircraft's tag drop, and for some unknown reason, the tag did not stay in the coast list like it should have. Due to equipment software failure, aircraft X traveled through our airspace and into adjacent airspace, having an near midair collision at 7000 ft with a departure off of azo. Aircraft X reported the near midair collision first attempting to call us 3 times, then azo while airborne. I was not working war at the time of the near midair collision, but based on the previous 15 mins, I find that a serious glitch in the ARTS iie system caused this aircraft to remove itself from our scope, effectively changing it from an idented displayed aircraft to a primary only.

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Original NASA ASRS Text

Title: PA28, NON XPONDER IFR ACFT, TRANSITS THROUGH GRR AIRSPACE AND ENTERS AZO AIRSPACE AND HAS NMAC WITH AZO DEPARTING D328. GRR CTLR BLAMES ARTS IIE PROGRAM.

Narrative: I WAS WORKING WAR APCH AT GRR. WE RECEIVED A MANUAL HDOF ON A PRIMARY ONLY ACFT. WE HAVE ASR-9 AND HAVE THE ABILITY TO MANUALLY TAG AND IDENT PRIMARIES, WHICH WAS DONE. THERE WERE 3 ACFT WITH PRIMARY/ALPHA NUMERIC TRACKS ON THEM, SO I NOTIFIED THE OS/RAS OF THIS FACT. I ISSUED TFC TO ACFT X, WORKED DILIGENTLY TO KEEP HIS ALPHA NUMERIC TRACK ON THE SCOPE, AS IT WAS HAVING TROUBLE STAYING ON INITIALLY. APPROX 15 MINS LATER, I DEBRIEFED THE RELIEVING SPECIALIST VIA PHYSICALLY POINTING TO 3 ACFT AND 3 CORRESPONDING STRIPS ASSOCIATED WITH EACH ACFT. THE RELIEVING SPECIALIST DID NOT SEE THE ACFT'S TAG DROP, AND FOR SOME UNKNOWN REASON, THE TAG DID NOT STAY IN THE COAST LIST LIKE IT SHOULD HAVE. DUE TO EQUIP SOFTWARE FAILURE, ACFT X TRAVELED THROUGH OUR AIRSPACE AND INTO ADJACENT AIRSPACE, HAVING AN NMAC AT 7000 FT WITH A DEP OFF OF AZO. ACFT X RPTED THE NMAC FIRST ATTEMPTING TO CALL US 3 TIMES, THEN AZO WHILE AIRBORNE. I WAS NOT WORKING WAR AT THE TIME OF THE NMAC, BUT BASED ON THE PREVIOUS 15 MINS, I FIND THAT A SERIOUS GLITCH IN THE ARTS IIE SYS CAUSED THIS ACFT TO REMOVE ITSELF FROM OUR SCOPE, EFFECTIVELY CHANGING IT FROM AN IDENTED DISPLAYED ACFT TO A PRIMARY ONLY.

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.