Narrative:

Relieved a fellow ATC specialist from the satellite radar position with moderate traffic. Included in the briefing were 2 aircraft en route from I69 to hao for instrument training. I was told the first aircraft was on his own navigation and cleared for the GPS runway 29 approach and the second aircraft was on a vector to establish additional spacing between the two. I expected the first aircraft to execute a straight-in approach and after I had established approximately 10 NM between the two aircraft. I issued a vector to join the localizer of runway 29 to the second aircraft. The first aircraft; however; did not execute a straight-in approach but executed a procedure turn. The aircraft passed within 1 NM of each other before I issued a vector to the second aircraft. Contributing factors: 1) I had just transitioned from 3+ yrs of working different shifts and sleep has been difficult. I was on about the third day of 4 or less hour of sleep. Since we did not instrument training on the previous shift; I was very unfamiliar or 'rusty' with the instrument training procedures. 3) the stars conflict alert sounded but I couldn't tell which targets were involved due to overlap. 4) due to the constant false alarms generated by the stars system; the fact that the conflict alert sounded did not get my immediate attention.

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Original NASA ASRS Text

Title: CVG CTLR EXPERIENCED OPERROR AT 3000 FT WHEN ACFT ON ILS APCH EXECUTED PROC TURN THAT CONFLICTED WITH SUCCEEDING TFC ON THE SAME APCH PROC.

Narrative: RELIEVED A FELLOW ATC SPECIALIST FROM THE SATELLITE RADAR POS WITH MODERATE TFC. INCLUDED IN THE BRIEFING WERE 2 ACFT ENRTE FROM I69 TO HAO FOR INST TRAINING. I WAS TOLD THE FIRST ACFT WAS ON HIS OWN NAV AND CLRED FOR THE GPS RWY 29 APCH AND THE SECOND ACFT WAS ON A VECTOR TO ESTABLISH ADDITIONAL SPACING BTWN THE TWO. I EXPECTED THE FIRST ACFT TO EXECUTE A STRAIGHT-IN APCH AND AFTER I HAD ESTABLISHED APPROX 10 NM BTWN THE TWO ACFT. I ISSUED A VECTOR TO JOIN THE LOC OF RWY 29 TO THE SECOND ACFT. THE FIRST ACFT; HOWEVER; DID NOT EXECUTE A STRAIGHT-IN APCH BUT EXECUTED A PROC TURN. THE ACFT PASSED WITHIN 1 NM OF EACH OTHER BEFORE I ISSUED A VECTOR TO THE SECOND ACFT. CONTRIBUTING FACTORS: 1) I HAD JUST TRANSITIONED FROM 3+ YRS OF WORKING DIFFERENT SHIFTS AND SLEEP HAS BEEN DIFFICULT. I WAS ON ABOUT THE THIRD DAY OF 4 OR LESS HR OF SLEEP. SINCE WE DID NOT INSTRUMENT TRAINING ON THE PREVIOUS SHIFT; I WAS VERY UNFAMILIAR OR 'RUSTY' WITH THE INST TRAINING PROCS. 3) THE STARS CONFLICT ALERT SOUNDED BUT I COULDN'T TELL WHICH TARGETS WERE INVOLVED DUE TO OVERLAP. 4) DUE TO THE CONSTANT FALSE ALARMS GENERATED BY THE STARS SYS; THE FACT THAT THE CONFLICT ALERT SOUNDED DID NOT GET MY IMMEDIATE ATTN.

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.