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.