Narrative:

I was on an IFR flight plan to sln and reported visibility contact of the airport to the ATC controller 16 NM east. I was told to contact sln tower and the tower advised me to report on a 4 mi right base to runway 35,. Tower asked for my position, which was 8.2 mi east. I reported 4 mi right base for runway 35 and continued inbound. At approximately 3 mi out tower advised another aircraft to report altitude. Tower operator (female) is replaced by a frantic voice (male) telling the other aircraft to immediately turn east. A few seconds later the aircraft passed below me approximately 100'. Tower advised me to turn right to heading of 180 degrees. Request makes no sense, so I asked him if he wanted me to turn north or south. He said north. Now I was over the approach end of runway 35, and was cleared to land. I believe tower did not communicate enough to aircraft advising of relative positions and headings. Supplemental information from acn 138040: small aircraft Y departed runway 35 sebnd. He was informed of small transport X inbound about 8 mi east of airport descending out of 4000'. The pilot acknowledged. A short time later I had small transport X in sight on about a 4-5 mi right base. We informed small aircraft Y that small transport X was ahead to his left on right base. He did not acknowledge. He was told again and didn't acknowledge. Then he was told to turn left and proceed east to avoid small transport X. He did not acknowledge. Small aircraft Y went underneath small transport X on right base, less than the required altitude for sep.

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Original NASA ASRS Text

Title: SMA CAME IN CLOSE PROX TO AN SMT WHILE IN THE TRAFFIC PATTERN.

Narrative: I WAS ON AN IFR FLT PLAN TO SLN AND RPTED VIS CONTACT OF THE ARPT TO THE ATC CTLR 16 NM E. I WAS TOLD TO CONTACT SLN TWR AND THE TWR ADVISED ME TO RPT ON A 4 MI RIGHT BASE TO RWY 35,. TWR ASKED FOR MY POS, WHICH WAS 8.2 MI E. I RPTED 4 MI RIGHT BASE FOR RWY 35 AND CONTINUED INBND. AT APPROX 3 MI OUT TWR ADVISED ANOTHER ACFT TO RPT ALT. TWR OPERATOR (FEMALE) IS REPLACED BY A FRANTIC VOICE (MALE) TELLING THE OTHER ACFT TO IMMEDIATELY TURN E. A FEW SECS LATER THE ACFT PASSED BELOW ME APPROX 100'. TWR ADVISED ME TO TURN RIGHT TO HDG OF 180 DEGS. REQUEST MAKES NO SENSE, SO I ASKED HIM IF HE WANTED ME TO TURN N OR S. HE SAID N. NOW I WAS OVER THE APCH END OF RWY 35, AND WAS CLRED TO LAND. I BELIEVE TWR DID NOT COMMUNICATE ENOUGH TO ACFT ADVISING OF RELATIVE POSITIONS AND HDGS. SUPPLEMENTAL INFO FROM ACN 138040: SMA Y DEPARTED RWY 35 SEBND. HE WAS INFORMED OF SMT X INBND ABOUT 8 MI E OF ARPT DSNDING OUT OF 4000'. THE PLT ACKNOWLEDGED. A SHORT TIME LATER I HAD SMT X IN SIGHT ON ABOUT A 4-5 MI RIGHT BASE. WE INFORMED SMA Y THAT SMT X WAS AHEAD TO HIS LEFT ON RIGHT BASE. HE DID NOT ACKNOWLEDGE. HE WAS TOLD AGAIN AND DIDN'T ACKNOWLEDGE. THEN HE WAS TOLD TO TURN LEFT AND PROCEED E TO AVOID SMT X. HE DID NOT ACKNOWLEDGE. SMA Y WENT UNDERNEATH SMT X ON RIGHT BASE, LESS THAN THE REQUIRED ALT FOR SEP.

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.