Narrative:

Air carrier X was approved at an altitude of 5000 ft on a route normally used at 7000-9000 ft in this particular airspace. There is another route very close to the edge of the airspace where this 5000 ft was approved. It is a little used route with a flow of 5000 ft also. Small transport Y entered the picutre on this route. I accepted handoff on air carrier X who checked in. I was distracted from air carrier X by other traffic and accepted handoff on small transport Y who was very close to my airspace. My attention was still in another part of the scope when small transport Y checked in. I answered him and within 20 seconds he reported a near midair with air carrier X. I never even saw the situation developing. My physical situation was less than usual. I was tired. Our sector is short staffed and controllers frequently go beyond 2 hours on position. The night before, I had very little sleep as I had an argument with a supervisor about being on position more than 2 hours, and it bothered me. Right before this position where the incident occurred, I was assigned a very busy position (combined) for a little over 2 hours.

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Original NASA ASRS Text

Title: ACR X HAD LTSS NMAC WITH SMT Y. EVASIVE ACTION TAKEN. SYS ERROR.

Narrative: ACR X WAS APPROVED AT AN ALT OF 5000 FT ON A RTE NORMALLY USED AT 7000-9000 FT IN THIS PARTICULAR AIRSPACE. THERE IS ANOTHER RTE VERY CLOSE TO THE EDGE OF THE AIRSPACE WHERE THIS 5000 FT WAS APPROVED. IT IS A LITTLE USED RTE WITH A FLOW OF 5000 FT ALSO. SMT Y ENTERED THE PICUTRE ON THIS RTE. I ACCEPTED HDOF ON ACR X WHO CHKED IN. I WAS DISTRACTED FROM ACR X BY OTHER TFC AND ACCEPTED HDOF ON SMT Y WHO WAS VERY CLOSE TO MY AIRSPACE. MY ATTN WAS STILL IN ANOTHER PART OF THE SCOPE WHEN SMT Y CHKED IN. I ANSWERED HIM AND WITHIN 20 SECONDS HE RPTED A NEAR MIDAIR WITH ACR X. I NEVER EVEN SAW THE SIT DEVELOPING. MY PHYSICAL SIT WAS LESS THAN USUAL. I WAS TIRED. OUR SECTOR IS SHORT STAFFED AND CTLRS FREQUENTLY GO BEYOND 2 HRS ON POS. THE NIGHT BEFORE, I HAD VERY LITTLE SLEEP AS I HAD AN ARGUMENT WITH A SUPVR ABOUT BEING ON POS MORE THAN 2 HRS, AND IT BOTHERED ME. RIGHT BEFORE THIS POS WHERE THE INCIDENT OCCURRED, I WAS ASSIGNED A VERY BUSY POS (COMBINED) FOR A LITTLE OVER 2 HRS.

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.