Narrative:

I was working R-1; the approach control to sig and sju airport. WX was VFR; but some clouds and rain present; mostly to the south. I work all inbounds to sju and sig; plus outbounds going north; west; and south. I accepted a handoff on the air carrier X coming in from the northeast at 6000 ft MSL. Just before the air carrier Y departed; I became preoccupied with an LR55; IFR inbound to sig; who was not reporting sig in sight for visual approach. The air carrier Y departed and I just climbed him to 10000 ft routinely (did not see the conflict with air carrier X. My initial perception was that air carrier X was far and not a factor; but I didn't analyze his speed; close to 300 KTS). I went back to the learjet landing sig; and still not visual; so I coordination on landline to ask sig to enter their airspace. All this affected my awareness of the conflict developing; I got too focused on one thing alone. I finally got the lear on his way; when I then realized (too late) of the loss of separation with air carrier X and air carrier Y. I should have switched to instrument approachs sooner when realizing WX was deteriorating and precluding visuals. Also; the fact I was 'focusing' too much on one thing; should've alerted me to 'look around' and scan my entire operation more.

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Original NASA ASRS Text

Title: ZSU CTLR EXPERIENCED OPERROR AT 6000 FT BTWN ARR AND DEP ACFT WHEN DISTR BY OTHER EVENTS IN ANOTHER SECTION OF ASSIGNED AIRSPACE.

Narrative: I WAS WORKING R-1; THE APCH CTL TO SIG AND SJU ARPT. WX WAS VFR; BUT SOME CLOUDS AND RAIN PRESENT; MOSTLY TO THE S. I WORK ALL INBOUNDS TO SJU AND SIG; PLUS OUTBOUNDS GOING N; W; AND S. I ACCEPTED A HDOF ON THE ACR X COMING IN FROM THE NE AT 6000 FT MSL. JUST BEFORE THE ACR Y DEPARTED; I BECAME PREOCCUPIED WITH AN LR55; IFR INBOUND TO SIG; WHO WAS NOT RPTING SIG IN SIGHT FOR VISUAL APCH. THE ACR Y DEPARTED AND I JUST CLBED HIM TO 10000 FT ROUTINELY (DID NOT SEE THE CONFLICT WITH ACR X. MY INITIAL PERCEPTION WAS THAT ACR X WAS FAR AND NOT A FACTOR; BUT I DIDN'T ANALYZE HIS SPD; CLOSE TO 300 KTS). I WENT BACK TO THE LEARJET LNDG SIG; AND STILL NOT VISUAL; SO I COORD ON LANDLINE TO ASK SIG TO ENTER THEIR AIRSPACE. ALL THIS AFFECTED MY AWARENESS OF THE CONFLICT DEVELOPING; I GOT TOO FOCUSED ON ONE THING ALONE. I FINALLY GOT THE LEAR ON HIS WAY; WHEN I THEN REALIZED (TOO LATE) OF THE LOSS OF SEPARATION WITH ACR X AND ACR Y. I SHOULD HAVE SWITCHED TO INST APCHS SOONER WHEN REALIZING WX WAS DETERIORATING AND PRECLUDING VISUALS. ALSO; THE FACT I WAS 'FOCUSING' TOO MUCH ON ONE THING; SHOULD'VE ALERTED ME TO 'LOOK AROUND' AND SCAN MY ENTIRE OP MORE.

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.