Narrative:

I was working moderate to heavy traffic when separation was lost between 2 IFR aircraft. Aircraft #1; P28L; was holding over shedd intersection at 4000 ft MSL (training). Aircraft #2 P28A; was northbound on V23 at 4000 ft MSL per our LOA with ZSE for aircraft en route to salem airport. It was a beautiful VFR day following a couple of months of rainy WX and the airplanes came out of nowhere. It can be quite a challenge to gear up for busy traffic after long stretches of slow traffic. Aircraft #2'2 route took him through almost every other aircraft that I was talking to. Had I taken him a different route and verbally coordination the change with ZSE there would not have been a problem. I also should have terminated VFR flight following on several aircraft so that I could give the IFR traffic my full attention. Contributing factors were that I had 3 different handoff controllers in a 40 min period which 1) created a bit of a distraction; and 2) did not allow for the person sitting next to me to be fully up to speed; and that aircraft #2 needed to be put on a new transponder code so that he could be handed off to center. I assigned aircraft #2 his new beacon code and dropped his data ag so that the new code could acquire. Unfortunately; I didn't listen closely enough for the pilot's readback -- there was none. The target on the scope continued northbound untagged and difficult to see for 4 mins before my supervisor noticed the problem. I turned aircraft #1 eastbound and aircraft #2 wbound; and descended aircraft #1 to 3000 ft MSL. Prescribed vertical and lateral separation was not maintained between the 2 aircraft. This unfortunate situation has taught me several valuable lessons.

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Original NASA ASRS Text

Title: EUG APCH CTLR EXPERIENCED OPERROR AT 4000 FT WHEN UNTAGGED IFR ACFT WAS ALLOWED TO CONFLICT WITH ANOTHER IFR ACFT.

Narrative: I WAS WORKING MODERATE TO HVY TFC WHEN SEPARATION WAS LOST BTWN 2 IFR ACFT. ACFT #1; P28L; WAS HOLDING OVER SHEDD INTXN AT 4000 FT MSL (TRAINING). ACFT #2 P28A; WAS NBOUND ON V23 AT 4000 FT MSL PER OUR LOA WITH ZSE FOR ACFT ENRTE TO SALEM ARPT. IT WAS A BEAUTIFUL VFR DAY FOLLOWING A COUPLE OF MONTHS OF RAINY WX AND THE AIRPLANES CAME OUT OF NOWHERE. IT CAN BE QUITE A CHALLENGE TO GEAR UP FOR BUSY TFC AFTER LONG STRETCHES OF SLOW TFC. ACFT #2'2 RTE TOOK HIM THROUGH ALMOST EVERY OTHER ACFT THAT I WAS TALKING TO. HAD I TAKEN HIM A DIFFERENT RTE AND VERBALLY COORD THE CHANGE WITH ZSE THERE WOULD NOT HAVE BEEN A PROB. I ALSO SHOULD HAVE TERMINATED VFR FLT FOLLOWING ON SEVERAL ACFT SO THAT I COULD GIVE THE IFR TFC MY FULL ATTN. CONTRIBUTING FACTORS WERE THAT I HAD 3 DIFFERENT HDOF CTLRS IN A 40 MIN PERIOD WHICH 1) CREATED A BIT OF A DISTR; AND 2) DID NOT ALLOW FOR THE PERSON SITTING NEXT TO ME TO BE FULLY UP TO SPEED; AND THAT ACFT #2 NEEDED TO BE PUT ON A NEW XPONDER CODE SO THAT HE COULD BE HANDED OFF TO CTR. I ASSIGNED ACFT #2 HIS NEW BEACON CODE AND DROPPED HIS DATA AG SO THAT THE NEW CODE COULD ACQUIRE. UNFORTUNATELY; I DIDN'T LISTEN CLOSELY ENOUGH FOR THE PLT'S READBACK -- THERE WAS NONE. THE TARGET ON THE SCOPE CONTINUED NBOUND UNTAGGED AND DIFFICULT TO SEE FOR 4 MINS BEFORE MY SUPVR NOTICED THE PROB. I TURNED ACFT #1 EBOUND AND ACFT #2 WBOUND; AND DSNDED ACFT #1 TO 3000 FT MSL. PRESCRIBED VERT AND LATERAL SEPARATION WAS NOT MAINTAINED BTWN THE 2 ACFT. THIS UNFORTUNATE SITUATION HAS TAUGHT ME SEVERAL VALUABLE LESSONS.

Data retrieved from NASA's ASRS site as of January 2009 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.