EMB110 CARGO FLC SIGHTS SAME TYPE ACFT HEADING STRAIGHT AT THEM WHEN THEY COMMENCE CLB AS CLRED.

Narrative

ATC (COLUMBUS APCH; 118.85) CLRED OUR FLT TO CLB TO 10000 FT MSL; OUT OF 8000 FT MSL; S OF FINDLAY VOR. WE WERE IN AND OUT OF CLOUD LAYERS THROUGHOUT OUR CLB; AND OUR VISIBILITY WAS SIGNIFICANTLY REDUCED BY HAZE. AS WE CAME OUT OF LAYER OF CLOUDS; I NOTICED ANOTHER ACFT SLIGHTLY ABOVE OUR ALT HEADING STRAIGHT FOR US. I IMMEDIATELY INTERRUPTED THE CLB; AND SIMULTANEOUSLY MADE A VIOLENT 90 DEG TURN TO THE R; WHILE INFORMING MY CAPT BY SAYING: 'WE GOT TFC AT 12 O'CLOCK POS.' WE WERE STILL TURNING WHEN THE OTHER ACFT CAME OFF OUR L SIDE; AT A DISTANCE OF APPROX 500 FT ABOVE US. THE OTHER ACFT NEVER CHANGED COURSE OR ALT DURING THE INCIDENT; AND NEVER MADE ANY CALLS TO COLUMBUS APCH. MY CAPT NOTIFIED ATC OF WHAT OCCURRED: 'HEY; COLUMBUS APCH; WE JUST HAD A TFC HERE AT OUR 12 O'CLOCK POS.' TO WHICH COLUMBUS RESPONDED: 'HUH; YEAH;...HE'S A VFR TFC SQUAWKING 1200; AND HE'S NOT TALKING TO ANYONE...' MY CAPT RESPONDED WITH THE FOLLOWING: 'YES; BUT YOU CLRED US TO CLB TO 10000 FT AND YOU NEVER TOLD US ABOUT HIM. WE HAD TO TAKE EVASIVE ACTION TO AVOID A COLLISION.' THE CTLR RESPONDED WITH MUTED SILENCE. THE REST OF OUR FLT PROCEEDED WITHOUT ANY FURTHER INCIDENT.