Narrative:

On approach to gsp, we were about 500 ft below the clouds with clearance to intercept the localizer (runway 4). We were at 4000 ft, about 7-8 mi from the runway and above the GS. ATC called traffic ahead and below us. This traffic (#2) was on our TCASII and apparently it was their presence that prohibited the controller from either clearing us for the approach or issuing a descent clearance on the localizer. ATC asked if we had visual contact with that aircraft and could maintain. My first officer told me yes. I relayed same, and ATC cleared us to 2600 ft while maintaining this traffic in sight. TCASII 'RA' occurred for this #2 traffic. I noticed additional converging traffic (#3) at 1 O'clock position, 300 ft above us (on TCASII). That traffic triggered a TCASII RA and almost immediate RA to 'descend now.' we descended in accord with the RA, and the clearance to 2600 ft. The aircraft (#3) passed almost directly above us at about 300-400 ft above us. Aircraft #2 and #3 were clear of clouds, as were we. Advised ATC of the RA involving aircraft #3 and they cleared us for the approach. Was quite thankful of the TCASII, and although we were completing a 13+ hour day, we reacted well to a potentially very hazardous or disastrous situation. Contributing factor perhaps: ATC workload in gsp area with convective activity in the area and high level of traffic.

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Original NASA ASRS Text

Title: NMAC BTWN A B737-200 DSNDING ON THE RWY 22 LOC FOR ILS AT 3200 FT AND A XING LIGHT TWIN NOT ISSUED AS TFC, 8 NM NE OF GSP, SC.

Narrative: ON APCH TO GSP, WE WERE ABOUT 500 FT BELOW THE CLOUDS WITH CLRNC TO INTERCEPT THE LOC (RWY 4). WE WERE AT 4000 FT, ABOUT 7-8 MI FROM THE RWY AND ABOVE THE GS. ATC CALLED TFC AHEAD AND BELOW US. THIS TFC (#2) WAS ON OUR TCASII AND APPARENTLY IT WAS THEIR PRESENCE THAT PROHIBITED THE CTLR FROM EITHER CLRING US FOR THE APCH OR ISSUING A DSCNT CLRNC ON THE LOC. ATC ASKED IF WE HAD VISUAL CONTACT WITH THAT ACFT AND COULD MAINTAIN. MY FO TOLD ME YES. I RELAYED SAME, AND ATC CLRED US TO 2600 FT WHILE MAINTAINING THIS TFC IN SIGHT. TCASII 'RA' OCCURRED FOR THIS #2 TFC. I NOTICED ADDITIONAL CONVERGING TFC (#3) AT 1 O'CLOCK POS, 300 FT ABOVE US (ON TCASII). THAT TFC TRIGGERED A TCASII RA AND ALMOST IMMEDIATE RA TO 'DSND NOW.' WE DSNDED IN ACCORD WITH THE RA, AND THE CLRNC TO 2600 FT. THE ACFT (#3) PASSED ALMOST DIRECTLY ABOVE US AT ABOUT 300-400 FT ABOVE US. ACFT #2 AND #3 WERE CLR OF CLOUDS, AS WERE WE. ADVISED ATC OF THE RA INVOLVING ACFT #3 AND THEY CLRED US FOR THE APCH. WAS QUITE THANKFUL OF THE TCASII, AND ALTHOUGH WE WERE COMPLETING A 13+ HR DAY, WE REACTED WELL TO A POTENTIALLY VERY HAZARDOUS OR DISASTROUS SIT. CONTRIBUTING FACTOR PERHAPS: ATC WORKLOAD IN GSP AREA WITH CONVECTIVE ACTIVITY IN THE AREA AND HIGH LEVEL OF TFC.

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.