NMAC. FLC OF AN MLG WAS GIVEN AN IMMEDIATE TURN BY DEP CTL DURING SID DEP DUE TO CONFLICTION WITH OVERTAKING A DEHAVILLAND DASH 8 (DH8) WITHIN 3 MI OF THE ARPT. IN ADDITION; THE RPTR STOPPED CLB AND SLOWED IN RESPONSE TO A TCASII RA SINCE THE WT OF HIS ACFT WOULD NOT PERMIT THE CLB RATE INSTRUCTED BY TCASII.

Narrative

WE WERE CLRED FOR TKOF RWY 36L RIGHT BEHIND A DH8. NO SPECIAL INSTRUCTIONS BY TWR. WE FLEW THE SID 2.5 DME AND TURNED TO 330 DEG HDG. WE HEARD DEP ASK THE DH8 IF HE WAS ON 330 DEG HDG. THE DH8 SAID; 'NO; I WAS ASSIGNED RWY HDG.' DEP HESITATED AND AFTER A FEW SECONDS THEY GAVE US AN IMMEDIATE R TURN TO 030 DEGS. WE HAD JUST CLEANED UP; SO I THEN TURNED IMMEDIATELY WITH AN APPROX 40-45 DEG BANK AS THE CTLR SOUNDED URGENT. WE OBSERVED THE DH8 JUST SLIGHTLY TO OUR AND 200 FT. OUR TCASII INSTRUCTED A CLB. I FELT OUR CLB RATE 'WAS NOT GOOD ENOUGH' AND WE WERE TOO CLOSE AND HVY TO GO OVER THE TOP. SO I STARTED TO LEVEL OFF AND SLOW MY RATE OF CLB; AS I COULD TELL WE WERE TOO CLOSE. THE TURN TO 030 DEGS SEEMED TO PUT US EVEN CLOSER. AT THAT POINT; THE CTLR WAS NOT TALKING AND I DSNDED TO 2800 FT AND LEVELED; GIVING US A 500 FT SEPARATION. ATC SAID; 'MAINTAIN YOUR ALT' AND THEN HE GAVE US A TURN ON COURSE AND CLB. I BELIEVE THE TWR FAILED TO DELETE THE SID AND GIVE US A TURN TO 330 DEGS JUST AT OUR TKOF POINT AND FAILED TO MAINTAIN SEPARATION. DEP WAS NOT SURE OF THE DH8'S HDG AND ONLY SEEMED TO AGGRAVATE THE SIT BY GIVING US THE TURN TO 030 DEGS AND NOT GIVING US THE DH8 DISTANCE AND POS. IF WE HAD NOT HAD TCASII I FEEL THE MISS WOULD HAVE BEEN MUCH CLOSER.