Medium Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Conflict NMAC
Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action; Flight Crew Executed Go Around / Missed Approach
Human Factors
Going into BIS while being vectored into the left downwind ATC advised of an aircraft on our right side; no altitude info. We did see the target on the display but never visually; the aircraft passed behind us; it was heading towards the airport. As we turned base to final and on Tower we could hear Tower calling out for the NORDO aircraft and to flash its light if he was landing at BIS. That's when I told the FO prepare for a go-around. Tower then asked if we wanted to go around and we said yes without hesitation; our position now was inside the marker for Runway 13 fully configured. After a moment of an awkward silence (because Tower was in shock this was occurring) Tower said 'go around the aircraft is at your 12 o' clock.' We started to go around when our jet started screaming 'TRAFFIC TRAFFIC' but no RA. That's when I made visual contact with the NORDO aircraft heading directly at us. All I could see is a single engine aircraft with its nose light on when I grabbed the controls and aggressively pitched nose up; went max power; and rolled right. When I pitched the nose up I lost contact with the conflicting aircraft. We came back around and landed.Caused by a pilot flying an aircraft into controlled airspace without a clearance and possibly without situational awareness. It's simple really; somebody flew over the landing runway of a towered airport and directly towards a landing jet and nearly caused a disaster. I feel my team had great situational awareness and understood fully the situation that was unfolding and we had a plan. We executed our plan and saved lives.
Air carrier Captain reported an NMAC with a light aircraft in the vicinity of BIS airport.