Narrative:

Level at 3;000 ft on right downwind for ILS 19 teb; abeam the field. Our TCAS auto populated on our nav display; with traffic at 12 o'clock; moving directly towards at co-altitude; 2 miles ahead. I started a left turn and then saw the traffic who also was in a turn in the same direction. I immediately reversed direction and began a climb. At the same time approach control called out the traffic. At 3;000 feet we were at the bottom of the class B airspace. The controller asked us to return to heading when able and asked what kind of aircraft. I thought it was a big piper cherokee but the other pilot thought it was a cirrus. He said he violated the class B airspace. We landed uneventfully at teb.

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Original NASA ASRS Text

Title: CE550 Captain reported an airborne conflict with a single engine low wing aircraft at 3;000 feet while on right downwind for Runway 19 at TEB. Evasive action is taken.

Narrative: Level at 3;000 Ft on right downwind for ILS 19 TEB; abeam the field. Our TCAS auto populated on our Nav Display; with traffic at 12 o'clock; moving directly towards at co-altitude; 2 miles ahead. I started a left turn and then saw the traffic who also was in a turn in the same direction. I immediately reversed direction and began a climb. At the same time approach control called out the traffic. At 3;000 feet we were at the bottom of the Class B airspace. The controller asked us to return to heading when able and asked what kind of aircraft. I thought it was a big Piper Cherokee but the other pilot thought it was a Cirrus. He said he violated the Class B Airspace. We landed uneventfully at TEB.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.