Narrative:

On-the-job training was being conducted on the hammond low altitude sector. Air carrier X was northbound out of new orleans, la. When he called center, he was nwbound turning slowly to a 350 degree heading, out of about 8000 climbing to 15000. Small transport Y was eastbound along V70 climbing VFR. (We were providing VFR flight following.) the radar trainee and I thought air carrier X would pass behind small transport X. Air carrier X was advised of the traffic and climbed to FL230. He acknowledged it. They were approximately 15 mi apart. I became aware that there was going to be a problem when air carrier X stopped his turn and was converging with small transport Y at a 90 degree angle. I hesitated, thinking the radar trainee would resolve the situation. Small transport Y was climbing through 11300 ft when I asked him if he was stopping at 11500 ft. The reply was 'negative, climbing to 13500 ft.' the air carrier was out of about 11200 ft. I told the VFR to stop his climb and called traffic telling him air carrier X, who was climbing faster, would climb above him. At this point, I'm not sure what happened but after the targets separated, air carrier X was below small transport Y. I told air carrier X traffic was no longer a factor. He said 'I know we had him on TCASII. Small transport Y said nothing. This is the radar student's first radar sector with about 90 of the allotted 120 hours. The sector was moderately busy and he was aware of the situation. I waited too long for him to resolve it. A 20 degree turn to the left, when they were 1 1/2-2 mins apart would have resolved the situation. When questioned, the student thought he was not required to take action after traffic was issued, unless the pilot requested it. If the pilot of air carrier X was responding to a TCASII resolution, descending to avoid, the situation became more dangerous because I told small transport Y to stop climbing.

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Original NASA ASRS Text

Title: ACR X HAD NMAC WITH VFR SMT Y. ACR X TCASII RA EVASIVE ACTION TAKEN FROM SMT Y. SEE AND AVOID.

Narrative: ON-THE-JOB TRAINING WAS BEING CONDUCTED ON THE HAMMOND LOW ALT SECTOR. ACR X WAS NBOUND OUT OF NEW ORLEANS, LA. WHEN HE CALLED CTR, HE WAS NWBOUND TURNING SLOWLY TO A 350 DEG HDG, OUT OF ABOUT 8000 CLBING TO 15000. SMT Y WAS EBOUND ALONG V70 CLBING VFR. (WE WERE PROVIDING VFR FLT FOLLOWING.) THE RADAR TRAINEE AND I THOUGHT ACR X WOULD PASS BEHIND SMT X. ACR X WAS ADVISED OF THE TFC AND CLBED TO FL230. HE ACKNOWLEDGED IT. THEY WERE APPROX 15 MI APART. I BECAME AWARE THAT THERE WAS GOING TO BE A PROBLEM WHEN ACR X STOPPED HIS TURN AND WAS CONVERGING WITH SMT Y AT A 90 DEG ANGLE. I HESITATED, THINKING THE RADAR TRAINEE WOULD RESOLVE THE SITUATION. SMT Y WAS CLBING THROUGH 11300 FT WHEN I ASKED HIM IF HE WAS STOPPING AT 11500 FT. THE REPLY WAS 'NEGATIVE, CLBING TO 13500 FT.' THE ACR WAS OUT OF ABOUT 11200 FT. I TOLD THE VFR TO STOP HIS CLB AND CALLED TFC TELLING HIM ACR X, WHO WAS CLBING FASTER, WOULD CLB ABOVE HIM. AT THIS POINT, I'M NOT SURE WHAT HAPPENED BUT AFTER THE TARGETS SEPARATED, ACR X WAS BELOW SMT Y. I TOLD ACR X TFC WAS NO LONGER A FACTOR. HE SAID 'I KNOW WE HAD HIM ON TCASII. SMT Y SAID NOTHING. THIS IS THE RADAR STUDENT'S FIRST RADAR SECTOR WITH ABOUT 90 OF THE ALLOTTED 120 HRS. THE SECTOR WAS MODERATELY BUSY AND HE WAS AWARE OF THE SITUATION. I WAITED TOO LONG FOR HIM TO RESOLVE IT. A 20 DEG TURN TO THE L, WHEN THEY WERE 1 1/2-2 MINS APART WOULD HAVE RESOLVED THE SITUATION. WHEN QUESTIONED, THE STUDENT THOUGHT HE WAS NOT REQUIRED TO TAKE ACTION AFTER TFC WAS ISSUED, UNLESS THE PLT REQUESTED IT. IF THE PLT OF ACR X WAS RESPONDING TO A TCASII RESOLUTION, DSNDING TO AVOID, THE SITUATION BECAME MORE DANGEROUS BECAUSE I TOLD SMT Y TO STOP CLBING.

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.