Narrative:

At the time this incident occurred I was working approximately 17 aircraft. I was working 3 or 4 southbound jet departures from slc on J9. I had 5 inbnds to slc that required crossing over the departures and positioning them 10 mi west of J9 at FL310. Also involved were several wbounds at FL350 and FL390 approximately 15-20 mi south of J84 and 1 eastbound at FL370 on about the same route. I also had 2 ebnds, one over mlf and one about 15 north of mlf at FL330. I received handoffs on 2 mlt's, mlt X at FL330 and mlt Y at FL370 from ZLA center about midway between J9 and J60. After the 2 aircraft were in my sector I took them off their filed routes to position them in the arrival gate. Shortly after I started them to the northwest, I noted that mlt Y was overtaking mlt X by about 40-50 KTS. I increased mlt X from M.71 to M.73. This was the biggest increase I could use west/O him overtaking other slc arrs in front of him. I turned mlt Y further to the northwest and reduced him by 15 KTS. As soon as mlt X cleared my southbound traffic I descended him to FL310 and started a handoff to sector 30. At that time sector 30 called my D man and pointed out wbound traffic on J84 large transport Z at FL310. I turned mlt X behind large transport Z and descended him to FL290. During this time I had been laddering mlt Y down above mlt X. When large transport Z was pointed out, mlt Y was still above FL330 I observed other traffic on J84 at FL330. I felt my only out was a big turn from 300 degrees to 360 degrees to go behind large transport Z also. I asked mlt Y what rate of descent he could give me. He said anything I wanted. I did a range/bearing from mlt Y to large transport Z. It read 5 mins I cleared him to reach FL290 within 3 mins. The range/bearing was incorrect because mlt Y was in a turn. 2 mins later mlt Y xed 4.8 mi behind large transport Z and overtook and came within 4.66 mi of mlt X. I was also working a widebody transport jet at FL410 descending and overtaking the 2 mlt's during this time, but was not involved in the loss of sep. I feel the situation occurred because I didn't use a big enough turn and because I didn't realize I had used bad time information received from the computer until it was too late. I also feel the late pointout on large transport Z required me to completely change my plans and get additional vertical sep. This sector is extremely complex. Maybe it's time to require slc arrs to be at FL290 to avoid crossing and descending and climbing through this en route traffic.

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Original NASA ASRS Text

Title: MLT VECTORED AND DESCENDED INTO LESS THAN STANDARD SEPARATION WITH ANOTHER MLT AND AN ACR LGT.

Narrative: AT THE TIME THIS INCIDENT OCCURRED I WAS WORKING APPROX 17 ACFT. I WAS WORKING 3 OR 4 SBND JET DEPS FROM SLC ON J9. I HAD 5 INBNDS TO SLC THAT REQUIRED XING OVER THE DEPS AND POSITIONING THEM 10 MI W OF J9 AT FL310. ALSO INVOLVED WERE SEVERAL WBOUNDS AT FL350 AND FL390 APPROX 15-20 MI S OF J84 AND 1 EBND AT FL370 ON ABOUT THE SAME ROUTE. I ALSO HAD 2 EBNDS, ONE OVER MLF AND ONE ABOUT 15 N OF MLF AT FL330. I RECEIVED HDOFS ON 2 MLT'S, MLT X AT FL330 AND MLT Y AT FL370 FROM ZLA CENTER ABOUT MIDWAY BTWN J9 AND J60. AFTER THE 2 ACFT WERE IN MY SECTOR I TOOK THEM OFF THEIR FILED ROUTES TO POS THEM IN THE ARR GATE. SHORTLY AFTER I STARTED THEM TO THE NW, I NOTED THAT MLT Y WAS OVERTAKING MLT X BY ABOUT 40-50 KTS. I INCREASED MLT X FROM M.71 TO M.73. THIS WAS THE BIGGEST INCREASE I COULD USE W/O HIM OVERTAKING OTHER SLC ARRS IN FRONT OF HIM. I TURNED MLT Y FURTHER TO THE NW AND REDUCED HIM BY 15 KTS. AS SOON AS MLT X CLRED MY SBND TFC I DSNDED HIM TO FL310 AND STARTED A HDOF TO SECTOR 30. AT THAT TIME SECTOR 30 CALLED MY D MAN AND POINTED OUT WBOUND TFC ON J84 LGT Z AT FL310. I TURNED MLT X BEHIND LGT Z AND DSNDED HIM TO FL290. DURING THIS TIME I HAD BEEN LADDERING MLT Y DOWN ABOVE MLT X. WHEN LGT Z WAS POINTED OUT, MLT Y WAS STILL ABOVE FL330 I OBSERVED OTHER TFC ON J84 AT FL330. I FELT MY ONLY OUT WAS A BIG TURN FROM 300 DEGS TO 360 DEGS TO GO BEHIND LGT Z ALSO. I ASKED MLT Y WHAT RATE OF DSCNT HE COULD GIVE ME. HE SAID ANYTHING I WANTED. I DID A RANGE/BEARING FROM MLT Y TO LGT Z. IT READ 5 MINS I CLRED HIM TO REACH FL290 WITHIN 3 MINS. THE RANGE/BEARING WAS INCORRECT BECAUSE MLT Y WAS IN A TURN. 2 MINS LATER MLT Y XED 4.8 MI BEHIND LGT Z AND OVERTOOK AND CAME WITHIN 4.66 MI OF MLT X. I WAS ALSO WORKING A WDB JET AT FL410 DSNDING AND OVERTAKING THE 2 MLT'S DURING THIS TIME, BUT WAS NOT INVOLVED IN THE LOSS OF SEP. I FEEL THE SITUATION OCCURRED BECAUSE I DIDN'T USE A BIG ENOUGH TURN AND BECAUSE I DIDN'T REALIZE I HAD USED BAD TIME INFO RECEIVED FROM THE COMPUTER UNTIL IT WAS TOO LATE. I ALSO FEEL THE LATE POINTOUT ON LGT Z REQUIRED ME TO COMPLETELY CHANGE MY PLANS AND GET ADDITIONAL VERT SEP. THIS SECTOR IS EXTREMELY COMPLEX. MAYBE IT'S TIME TO REQUIRE SLC ARRS TO BE AT FL290 TO AVOID XING AND DSNDING AND CLBING THROUGH THIS ENRTE TFC.

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.