Narrative:

Climbing to cleared altitude of FL230 noticed a TCASII target at 11 O'clock position and 4-5 mi. We were passing 15500 ft and he was at 17500 ft. We were climbing at about 3000 FPM so I deselected VNAV by rolling vertical speed to +1--- FPM climb and tried to acquire visual. About 10-20 seconds later, center called a 'VFR target at 17500 ft, but gave no instructions to turn or stop the climb. At almost the same time, a TCASII RA went off and it directed a leveloff. I quickly complied and we all (captain, myself and FAA jumpseater) acquired visual a second or two later. Target was a flight test jet in primary paint. We notified center that we had stopped our climb for a TCASII RA and I began a shallow descent from 16600 ft to 16500 ft as he passed right overhead at 17500 ft. After clear of conflict we continued to climb and were quickly switched to another frequency. It didn't seem like we got much help from ATC that day so thank goodness for TCASII. By the way, the climb corridor seems an odd place to be doing flight test. The next controller said our traffic was still squawking a discrete code, but was operating VFR. Not quite sure what that means. Anyway, TCASII was invaluable in keeping this event from becoming more serious.

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Original NASA ASRS Text

Title: B737 CLBING TO FL230 WITH ZKC EXPERIENCED TCASII RA WITH VFR TFC AT 17500 FT.

Narrative: CLBING TO CLRED ALT OF FL230 NOTICED A TCASII TARGET AT 11 O'CLOCK POS AND 4-5 MI. WE WERE PASSING 15500 FT AND HE WAS AT 17500 FT. WE WERE CLBING AT ABOUT 3000 FPM SO I DESELECTED VNAV BY ROLLING VERT SPD TO +1--- FPM CLB AND TRIED TO ACQUIRE VISUAL. ABOUT 10-20 SECONDS LATER, CTR CALLED A 'VFR TARGET AT 17500 FT, BUT GAVE NO INSTRUCTIONS TO TURN OR STOP THE CLB. AT ALMOST THE SAME TIME, A TCASII RA WENT OFF AND IT DIRECTED A LEVELOFF. I QUICKLY COMPLIED AND WE ALL (CAPT, MYSELF AND FAA JUMPSEATER) ACQUIRED VISUAL A SECOND OR TWO LATER. TARGET WAS A FLT TEST JET IN PRIMARY PAINT. WE NOTIFIED CTR THAT WE HAD STOPPED OUR CLB FOR A TCASII RA AND I BEGAN A SHALLOW DSCNT FROM 16600 FT TO 16500 FT AS HE PASSED RIGHT OVERHEAD AT 17500 FT. AFTER CLR OF CONFLICT WE CONTINUED TO CLB AND WERE QUICKLY SWITCHED TO ANOTHER FREQ. IT DIDN'T SEEM LIKE WE GOT MUCH HELP FROM ATC THAT DAY SO THANK GOODNESS FOR TCASII. BY THE WAY, THE CLB CORRIDOR SEEMS AN ODD PLACE TO BE DOING FLT TEST. THE NEXT CTLR SAID OUR TFC WAS STILL SQUAWKING A DISCRETE CODE, BUT WAS OPERATING VFR. NOT QUITE SURE WHAT THAT MEANS. ANYWAY, TCASII WAS INVALUABLE IN KEEPING THIS EVENT FROM BECOMING MORE SERIOUS.

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.