NMAC AVOIDED AS TCASII TA STARTS DC9 FLC EVASIVE ACTION TURN DSCNT. 2 DEP ACFT ON CONVERGING TRACKS. TA NOT GIVEN.

Narrative

JUST AFTER TKOF FROM RWY 10C AT PIT WE RECEIVED A TA ON THE TCASII. IT INDICATED ANOTHER ACFT WE WERE UNAWARE OF; CLBING 800 FT ABOVE US AND PARALLELING OUR COURSE. AT 2500 FT WE SPOTTED THE ACFT VISUALLY. IT WAS APPARENT THAT AT OUR RATE OF CLB WE WOULD HIT THE ACFT. WE THEN TOOK EVASIVE ACTION AND TURNED TO 060 DEG HDG AND DSNDED TO 2000 FT MSL. IT WAS ONLY AFTER WE STARTED THE EVASIVE ACTION THAT WE RECEIVED AN RA FROM THE TCASII. SUPPLEMENTAL INFO FROM ACN 359847: THE CAPT INITIATED AN EVASIVE MANEUVER -- L TURN AND A DSCNT BACK TO 2000 FT (800 FT AGL). WE WERE CLOSE ENOUGH TO IDENT THE TYPE ACFT. IF WE HAD NOT PERFORMED THE MANEUVER; I CAN SAY WITHOUT A DOUBT; WE WOULD HAVE BEEN THE LEAD STORY ON THE NEWS. TCASII DEFINITELY SAVED THE DAY. WE CALLED ATC WHEN WE ARRIVED AT OUR DEST. THE CARAVAN HAD TAKEN OFF BEFORE US ON RWY 14. TWR HAD INITIALLY GIVEN HIM RWY HDG THEN GAVE HIM A L TURN TO 120 DEGS AND TURNED HIM OVER TO DEP. WE THEN DEPARTED ON RWY 10C AND MAINTAINED RWY HDG. WINDS AT THE SURFACE WERE 130 DEGS AT 15 KTS AND APPARENTLY MORE OUT OF THE S HIGHER UP. TWR DIDN'T TELL DEP THEY HAD TURNED THE CARAVAN TO 120 DEGS. AFTER COMPLETING OUR EVASIVE MANEUVER WE QUERIED ATC ABOUT THE TFC; THEIR ONLY RESPONSE WAS HE'S ON A 140 DEG HDG. NOTHING ABOUT THE FACT WE WOULD HAVE CLBED THROUGH HIS ALT. WHEN WE WERE CLR OF THE TFC WE CLBED BACK UP TO OUR ASSIGNED ALT; 5000 FT.