Narrative:

Detroit metropolitan has 4 inbound fixes for aircraft landing at metropolitan. At the time of the operational error, I was working the north feeder position which included the northwest and the northeast inbound fixes. Small aircraft X was an overflt from the northwest to the southeast at 9000. Air carrier Y was inbound to metropolitan from the northeast and vectored at 10,000 southwest to detroit metropolitan. I descended air carrier Y to 8000. When I saw the confliction, I turned air carrier Y to avoid small aircraft X and lost separation before I could gain course divergence. ZOB is to insure that aircraft cross the northeast inbound fix at 10,000. ZOB was consistently vectoring 8 to 10 mi north of the fix which forced me to point out all the aircraft to 2 adjacent sectors. At the time of the error we were experiencing an intermittent loss of flight data (excessive coasting). This problem had been reported several times over the last 2 weeks. Even with the above distractions I should not have descended air carrier Y through small aircraft X. I believe a contributing factor to the error was that I was very tired, due to the schedule we are required to work (5 to 6 days a week. 5 different shifts. Afternoons to a day to a midnight). I believe the subject of scheduling should be addressed by the FAA as it adds to: a) controller fatigue and probably many. B) short tempers. C) poor health. Other things.

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Original NASA ASRS Text

Title: ACR WAS DESCENDED THROUGH THE ALT OF AN SMA RESULTING IN LESS THAN STANDARD SEPARATION.

Narrative: DETROIT METRO HAS 4 INBND FIXES FOR ACFT LNDG AT METRO. AT THE TIME OF THE OPERATIONAL ERROR, I WAS WORKING THE N FEEDER POSITION WHICH INCLUDED THE NW AND THE NE INBND FIXES. SMA X WAS AN OVERFLT FROM THE NW TO THE SE AT 9000. ACR Y WAS INBND TO METRO FROM THE NE AND VECTORED AT 10,000 SW TO DETROIT METRO. I DESCENDED ACR Y TO 8000. WHEN I SAW THE CONFLICTION, I TURNED ACR Y TO AVOID SMA X AND LOST SEPARATION BEFORE I COULD GAIN COURSE DIVERGENCE. ZOB IS TO INSURE THAT ACFT CROSS THE NE INBND FIX AT 10,000. ZOB WAS CONSISTENTLY VECTORING 8 TO 10 MI N OF THE FIX WHICH FORCED ME TO POINT OUT ALL THE ACFT TO 2 ADJACENT SECTORS. AT THE TIME OF THE ERROR WE WERE EXPERIENCING AN INTERMITTENT LOSS OF FLT DATA (EXCESSIVE COASTING). THIS PROBLEM HAD BEEN REPORTED SEVERAL TIMES OVER THE LAST 2 WEEKS. EVEN WITH THE ABOVE DISTRACTIONS I SHOULD NOT HAVE DESCENDED ACR Y THROUGH SMA X. I BELIEVE A CONTRIBUTING FACTOR TO THE ERROR WAS THAT I WAS VERY TIRED, DUE TO THE SCHEDULE WE ARE REQUIRED TO WORK (5 TO 6 DAYS A WEEK. 5 DIFFERENT SHIFTS. AFTERNOONS TO A DAY TO A MIDNIGHT). I BELIEVE THE SUBJECT OF SCHEDULING SHOULD BE ADDRESSED BY THE FAA AS IT ADDS TO: A) CTLR FATIGUE AND PROBABLY MANY. B) SHORT TEMPERS. C) POOR HEALTH. OTHER THINGS.

Data retrieved from NASA's ASRS site as of August 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.