Narrative:

Large transport X msp J45 bna mco was vectored 15 degrees right of J45 while northwest of stl for large transport Y, who was northbound on J137. When it was determined that large transport X would pass clear of large transport Y, large transport X was reclred direct stl, on course. Large transport X missed stl on his turn and was headed east to apparently intercept J45 southeast of stl. In doing so he picked up jet streams on tail increasing ground speed considerable. Trnee, who was working sector, cleared large transport X to fly present heading to join J45 and change to next sector frequency. Instrument immediately told large transport X to turn 30 degrees right for traffic. Large transport X replied: was that for large transport X?' instrument replied affirmative! Large transport Y was then turned 30 degrees right immediately. At this time large transport X transmitted, 'we've got the heading to join, good day.' no response from large transport X after that. Sep was lost shortly thereafter. This controller (instrument) believes contributing factors were: sectors combined due to frequency failure for ultra hi sector; jet stream winds in excess of 125 KTS; and misunderstanding of, or failure of, flight crew to receive clearance for 30 degree right turn. Supplemental information from acn 100079: radar instrument assumed control and told large transport X to turn 30 degrees right, vector for traffic before he could acknowledge for the original clearance to join J45. Large transport X questioned if the 30 degree right turn was for him. The instrument replied, 'affirmative (pause) large transport Y turn 30 degrees right and I need it right now.' large transport Y questioned if that clearance was for him. Instrument repeated the instructions and large transport Y acknowledged.

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Original NASA ASRS Text

Title: ACR LGT'S ON CONFLICTING COURSES AT SAME ALT VECTORED TOO LATE TO PRESERVE SEPARATION.

Narrative: LGT X MSP J45 BNA MCO WAS VECTORED 15 DEGS RIGHT OF J45 WHILE NW OF STL FOR LGT Y, WHO WAS NBOUND ON J137. WHEN IT WAS DETERMINED THAT LGT X WOULD PASS CLR OF LGT Y, LGT X WAS RECLRED DIRECT STL, ON COURSE. LGT X MISSED STL ON HIS TURN AND WAS HEADED E TO APPARENTLY INTERCEPT J45 SE OF STL. IN DOING SO HE PICKED UP JET STREAMS ON TAIL INCREASING GND SPD CONSIDERABLE. TRNEE, WHO WAS WORKING SECTOR, CLRED LGT X TO FLY PRESENT HDG TO JOIN J45 AND CHANGE TO NEXT SECTOR FREQ. INSTR IMMEDIATELY TOLD LGT X TO TURN 30 DEGS RIGHT FOR TFC. LGT X REPLIED: WAS THAT FOR LGT X?' INSTR REPLIED AFFIRMATIVE! LGT Y WAS THEN TURNED 30 DEGS RIGHT IMMEDIATELY. AT THIS TIME LGT X XMITTED, 'WE'VE GOT THE HDG TO JOIN, GOOD DAY.' NO RESPONSE FROM LGT X AFTER THAT. SEP WAS LOST SHORTLY THEREAFTER. THIS CTLR (INSTR) BELIEVES CONTRIBUTING FACTORS WERE: SECTORS COMBINED DUE TO FREQ FAILURE FOR ULTRA HI SECTOR; JET STREAM WINDS IN EXCESS OF 125 KTS; AND MISUNDERSTANDING OF, OR FAILURE OF, FLT CREW TO RECEIVE CLRNC FOR 30 DEG RIGHT TURN. SUPPLEMENTAL INFO FROM ACN 100079: RADAR INSTR ASSUMED CTL AND TOLD LGT X TO TURN 30 DEGS RIGHT, VECTOR FOR TFC BEFORE HE COULD ACKNOWLEDGE FOR THE ORIGINAL CLRNC TO JOIN J45. LGT X QUESTIONED IF THE 30 DEG RIGHT TURN WAS FOR HIM. THE INSTR REPLIED, 'AFFIRMATIVE (PAUSE) LGT Y TURN 30 DEGS RIGHT AND I NEED IT RIGHT NOW.' LGT Y QUESTIONED IF THAT CLRNC WAS FOR HIM. INSTR REPEATED THE INSTRUCTIONS AND LGT Y ACKNOWLEDGED.

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.