Narrative:

Aircraft #1, medium large transport X at FL330, assigned mach .82 plus, approximately heading 350 direct ilm VORTAC. Aircraft #2, medium large transport Y at FL330, assigned mach .80 minus, approximately heading 010 direct ilm VORTAC. Know wind component was 290 and 110 KTS. (Report approximately 20 mins old). As acfts #1 and #2 progressed toward ilm I turned #2 30 degrees right to fall in trail behind #1. This original vector was done approximately when #2 was 25 mi southwest of #1. I knew that the sep would probably fall to less than 10 mi so I put the 6 mi sep circle around #2. When the sep fell to approximately 15 mi I turned #2 further right heading 080. As #2 was passing behind #1 and #1's radar target was approximately 7 plus mi ahead (well outside the 6 mi circle) #1's radar target jumped inside the circle about 4 mi from #2. The next radar update showed #1 back outside the circle. The next radar update indicated #1 was back inside the circle within 4 mi of #2. At this point I lost all confidence in the radar data heading of 010. I immediately followed this with a clearance for #2 to descend to FL310, followed by 'expedite descent.' sep was lost after I resorted to turning #2/330 and #1/010 due to the winds. Even though 5 controllers observed the target jumps of #1 in and out of the circle around #2, quality assurance would only honor the data produced for them. This same data indicated that if I had left #2 on the last heading assigned before losing confidence in the radar data and turning #2 west again that the aircraft would have passed with 6 plus mi of sep. In retrospect, I doubt if I would have done anything differently as I shoot for 5 mi, plus one for me and one for the kid. The quality assurance office advises that they are pursuing he erratic data that several of us observed, but I doubt it seriously. This incident occurred at a 'sort box' for jacksonville center's mosaic radar system. #1 was being tracked by chs/jedburg site until incident and the jumped to fay/ benson, then back to chs/then back to fay and continued to do so until both aircraft were being tracked by fay. This is a known problem but this was a severe case and especially when running close sep. Supplemental information from acn 173347. The conflict alert and immediate alert went off again. ZJX climbed medium large transport Y to FL320 because medium large transport X also northbound was at FL330 and these two passed within 2 mi at FL330 and FL320. Then, ZJX turned both medium large transport X and medium large transport a to the west. When they were horizontally separated, ZJX turned them back on course.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION OCCURRED BETWEEN MLG X AND MLG Y. CTLR WAS VECTORING MLG Y AWAY FROM MLG X WHEH LESS THAN STANDARD SEPARATION OCCURRED BETWEEN MLG Y AND MLG A.

Narrative: ACFT #1, MLG X AT FL330, ASSIGNED MACH .82 PLUS, APPROX HDG 350 DIRECT ILM VORTAC. ACFT #2, MLG Y AT FL330, ASSIGNED MACH .80 MINUS, APPROX HDG 010 DIRECT ILM VORTAC. KNOW WIND COMPONENT WAS 290 AND 110 KTS. (RPT APPROX 20 MINS OLD). AS ACFTS #1 AND #2 PROGRESSED TOWARD ILM I TURNED #2 30 DEGS R TO FALL IN TRAIL BEHIND #1. THIS ORIGINAL VECTOR WAS DONE APPROX WHEN #2 WAS 25 MI SW OF #1. I KNEW THAT THE SEP WOULD PROBABLY FALL TO LESS THAN 10 MI SO I PUT THE 6 MI SEP CIRCLE AROUND #2. WHEN THE SEP FELL TO APPROX 15 MI I TURNED #2 FURTHER R HDG 080. AS #2 WAS PASSING BEHIND #1 AND #1'S RADAR TARGET WAS APPROX 7 PLUS MI AHEAD (WELL OUTSIDE THE 6 MI CIRCLE) #1'S RADAR TARGET JUMPED INSIDE THE CIRCLE ABOUT 4 MI FROM #2. THE NEXT RADAR UPDATE SHOWED #1 BACK OUTSIDE THE CIRCLE. THE NEXT RADAR UPDATE INDICATED #1 WAS BACK INSIDE THE CIRCLE WITHIN 4 MI OF #2. AT THIS POINT I LOST ALL CONFIDENCE IN THE RADAR DATA HDG OF 010. I IMMEDIATELY FOLLOWED THIS WITH A CLRNC FOR #2 TO DSND TO FL310, FOLLOWED BY 'EXPEDITE DSNT.' SEP WAS LOST AFTER I RESORTED TO TURNING #2/330 AND #1/010 DUE TO THE WINDS. EVEN THOUGH 5 CTLRS OBSERVED THE TARGET JUMPS OF #1 IN AND OUT OF THE CIRCLE AROUND #2, QUALITY ASSURANCE WOULD ONLY HONOR THE DATA PRODUCED FOR THEM. THIS SAME DATA INDICATED THAT IF I HAD LEFT #2 ON THE LAST HDG ASSIGNED BEFORE LOSING CONFIDENCE IN THE RADAR DATA AND TURNING #2 W AGAIN THAT THE ACFT WOULD HAVE PASSED WITH 6 PLUS MI OF SEP. IN RETROSPECT, I DOUBT IF I WOULD HAVE DONE ANYTHING DIFFERENTLY AS I SHOOT FOR 5 MI, PLUS ONE FOR ME AND ONE FOR THE KID. THE QUALITY ASSURANCE OFFICE ADVISES THAT THEY ARE PURSUING HE ERRATIC DATA THAT SEVERAL OF US OBSERVED, BUT I DOUBT IT SERIOUSLY. THIS INCIDENT OCCURRED AT A 'SORT BOX' FOR JACKSONVILLE CTR'S MOSAIC RADAR SYS. #1 WAS BEING TRACKED BY CHS/JEDBURG SITE UNTIL INCIDENT AND THE JUMPED TO FAY/ BENSON, THEN BACK TO CHS/THEN BACK TO FAY AND CONTINUED TO DO SO UNTIL BOTH ACFT WERE BEING TRACKED BY FAY. THIS IS A KNOWN PROB BUT THIS WAS A SEVERE CASE AND ESPECIALLY WHEN RUNNING CLOSE SEP. SUPPLEMENTAL INFO FROM ACN 173347. THE CONFLICT ALERT AND IMMEDIATE ALERT WENT OFF AGAIN. ZJX CLBED MLG Y TO FL320 BECAUSE MLG X ALSO NBND WAS AT FL330 AND THESE TWO PASSED WITHIN 2 MI AT FL330 AND FL320. THEN, ZJX TURNED BOTH MLG X AND MLG A TO THE W. WHEN THEY WERE HORIZLY SEPARATED, ZJX TURNED THEM BACK ON COURSE.

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.