BE90 HAS NMAC WITH UNKNOWN ACFT SHORTLY AFTER TKOF.

Narrative

TKOF CLRNC WAS RECEIVED BEFORE REACHING THE RWY; THE BEFORE TKOF CHKLIST WAS COMPLETED AND THE LINE-UP CHKS COMPLETED ON THE RWY. AT APPROX 40 KTS I CALLED 'ABORT; ABORT' (SIMULATED TKOF ABORT); THE INSPECTOR RESPONDED APPROPRIATELY BY APPLYING THE BRAKES AND REVERSE THRUST. I IMMEDIATELY ADVISED HIM TO RELAX AND CONTINUE THE TKOF ROLL. I TRIMMED THE PWR LEVERS AND CALLED FOR ROTATION AT ABOUT 95 KIAS; I CALLED POSITIVE RATE AND THE INSPECTOR CALLED 'GEAR UP.' I RECALL I WAS SCANNING THE INSTS; CHKED THAT TORQUES AND TEMPS WERE WITHIN LIMITS; AND CONFIRMED THE GEAR WAS RETRACTING; WHEN I HEARD THE WORD 'AIRPLANE;' WHICH I THOUGHT WAS UNUSUAL. I IMMEDIATELY LOOKED OUT IN FRONT AND SAW A LOW WING ACFT DIRECTLY AHEAD; AT OUR ALT; AND CLOSING FAST. THE ACFT DID NOT ALTER COURSE; SO I IMMEDIATELY TOOK THE CTLS AND PERFORMED AN AGGRESSIVE HARD L BANK. I CALLED 'MY ACFT' AND ROLLED WINGS LEVEL AFTER APPROX 60 DEGS OF TURN AT WHICH TIME I QUERIED THE TWR. TWR IMMEDIATELY QUERIED 2 ACFT; ONE OF WHICH WAS ON A R BASE TO RWY 33 AND SHOULD NOT HAVE BEEN A FACTOR. AT THAT TIME WE WERE HANDED OFF TO DEP. I GAVE THE ACFT CTLS BACK TO THE INSPECTOR AND COMPLETED THE AFTER TKOF CHKLIST. I DECIDED TO CONTINUE THE FLT. I BELIEVE THAT WE LIKELY CAME WITHIN ABOUT 200-300 FT HORIZLY OF THIS ACFT AT AN ALT OF ABOUT 100 FT AGL.