Narrative:

The problem arose when a DC9 X departing northbound off the airport was turned sbound on course while a BE33 Y was nwbound over the main bang of the radar antenna. Just before all this occurred, the traffic had been light for awhile. Within 2 1/2 mins the complexity jumped to 22 xmissions. I had just been previously engaged resolving a TA situation between 2 VFR aircraft orbiting in the vicinity of the airport at the same altitude, one of which was not on my frequency due to the fact the position was split 20 mins earlier and 1 aircraft was still on the other frequency (which we discovered later). I had to issue a traffic alert to resolve that conflict which was occurring while the DC9 checked in. 8 seconds after that was done, I turned the DC9 left to heading 220. After that center called and wanted me to turn and climb someone else, which I did, but the pilot read back FL220 instead of FL270 so I had to go back and correct him. I also had other departures checking in, had to terminate some VFR's and do a couple of point outs. During this time a BE33, which had checked in 45 mi to the southeast and was overflying the airport to the northwest at 060 ft, was over the main bang. The last time I remembered looking at him was when he was around 8 mi southeast of the airport and I thought he was safe because I had my departures stopped at 040 ft for the orbiting aircraft to the northwest. When the DC9 checked in, I saw he was clear of my orbiters so I climbed him to 100 ft which I would have done even if I had seen the BE33 over the bang whose tag had dropped. When I turned the DC9 to a 200 heading on course there was no ARTS tag on the BE33 so I didn't see him. Suddenly the tag appeared the next time I looked at the DC9. My immediate reaction was to stop his climb but I saw he was already climbing through 050 so I knew that would be impossible. My next thought was to stop his turn not knowing that he had already completed it, so I turned him right to 280 and called traffic at 11 O'clock and 3 mi. I then realized he had already completed his turn and that he would now be turning into the BE33 so I told him to expedite through 060 and called traffic again. He finally ended up going over top of the BE33 by at least 300 ft. I never had time to call traffic to the BE33.

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Original NASA ASRS Text

Title: ACR X CLB THROUGH OCCUPIED ALT HAD LTSS FROM SMA Y. SYS ERROR.

Narrative: THE PROB AROSE WHEN A DC9 X DEPARTING NBOUND OFF THE ARPT WAS TURNED SBOUND ON COURSE WHILE A BE33 Y WAS NWBOUND OVER THE MAIN BANG OF THE RADAR ANTENNA. JUST BEFORE ALL THIS OCCURRED, THE TFC HAD BEEN LIGHT FOR AWHILE. WITHIN 2 1/2 MINS THE COMPLEXITY JUMPED TO 22 XMISSIONS. I HAD JUST BEEN PREVIOUSLY ENGAGED RESOLVING A TA SIT BTWN 2 VFR ACFT ORBITING IN THE VICINITY OF THE ARPT AT THE SAME ALT, ONE OF WHICH WAS NOT ON MY FREQ DUE TO THE FACT THE POS WAS SPLIT 20 MINS EARLIER AND 1 ACFT WAS STILL ON THE OTHER FREQ (WHICH WE DISCOVERED LATER). I HAD TO ISSUE A TFC ALERT TO RESOLVE THAT CONFLICT WHICH WAS OCCURRING WHILE THE DC9 CHKED IN. 8 SECONDS AFTER THAT WAS DONE, I TURNED THE DC9 L TO HDG 220. AFTER THAT CTR CALLED AND WANTED ME TO TURN AND CLB SOMEONE ELSE, WHICH I DID, BUT THE PLT READ BACK FL220 INSTEAD OF FL270 SO I HAD TO GO BACK AND CORRECT HIM. I ALSO HAD OTHER DEPS CHKING IN, HAD TO TERMINATE SOME VFR'S AND DO A COUPLE OF POINT OUTS. DURING THIS TIME A BE33, WHICH HAD CHKED IN 45 MI TO THE SE AND WAS OVERFLYING THE ARPT TO THE NW AT 060 FT, WAS OVER THE MAIN BANG. THE LAST TIME I REMEMBERED LOOKING AT HIM WAS WHEN HE WAS AROUND 8 MI SE OF THE ARPT AND I THOUGHT HE WAS SAFE BECAUSE I HAD MY DEPS STOPPED AT 040 FT FOR THE ORBITING ACFT TO THE NW. WHEN THE DC9 CHKED IN, I SAW HE WAS CLR OF MY ORBITERS SO I CLBED HIM TO 100 FT WHICH I WOULD HAVE DONE EVEN IF I HAD SEEN THE BE33 OVER THE BANG WHOSE TAG HAD DROPPED. WHEN I TURNED THE DC9 TO A 200 HDG ON COURSE THERE WAS NO ARTS TAG ON THE BE33 SO I DIDN'T SEE HIM. SUDDENLY THE TAG APPEARED THE NEXT TIME I LOOKED AT THE DC9. MY IMMEDIATE REACTION WAS TO STOP HIS CLB BUT I SAW HE WAS ALREADY CLBING THROUGH 050 SO I KNEW THAT WOULD BE IMPOSSIBLE. MY NEXT THOUGHT WAS TO STOP HIS TURN NOT KNOWING THAT HE HAD ALREADY COMPLETED IT, SO I TURNED HIM R TO 280 AND CALLED TFC AT 11 O'CLOCK AND 3 MI. I THEN REALIZED HE HAD ALREADY COMPLETED HIS TURN AND THAT HE WOULD NOW BE TURNING INTO THE BE33 SO I TOLD HIM TO EXPEDITE THROUGH 060 AND CALLED TFC AGAIN. HE FINALLY ENDED UP GOING OVER TOP OF THE BE33 BY AT LEAST 300 FT. I NEVER HAD TIME TO CALL TFC TO THE BE33.

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.