BAe 125 Series 800
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Flight Crew Last 90 Days 47; Flight Crew Total 9000; Flight Crew Type 5630
Situational Awareness
Conflict NMAC
Flight Crew Took Evasive Action
Human Factors
While at 4000 ft we just passed BDR VOR headed northwest to RYMES intersection and had to make evasive maneuvers to avoid a collision with a Katana aircraft headed southwest bound also at 4000 ft. The meteorological conditions were 5 mi visibility and a scattered to broken layer at 3000 ft. The Katana was white without its transponder operating and no radio communications with ATC. ATC didn't have any target appear on their screen either. TCAS didn't show a target nor did it alert us to the aircraft. A turn was employed to keep us away from the Katana as it passed within 100 ft of our wing.
HS125 Captain reported an NMAC with a DA20 in the vicinity of BDR.