Embraer Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 50; Flight Crew Total 18000; Flight Crew Type 100
Communication Breakdown; Confusion
Conflict NMAC; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Flight Crew Took Evasive Action; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Clearance
Procedure; Human Factors
This was the first test flight of a Aircraft X after production. The aircraft had TCAS I installed but not TCAS II. I was established on downwind north of ZZZ at 3;000 ft. being vectors by Approach control for an ILS to Runway XXR at ZZZ. Prior to the base turn I noted on TCAS an aircraft co altitude at my 10 O'clock position. When ATC gave us a base turn I asked the Controller if he had the 10 o'clock traffic on radar as he was turning us toward the traffic. He stated that the traffic was moving southwest and therefore not a factor. After completing the turn south on a base leg I identified the traffic visually. I determined we were co altitude moving rapidly toward each other and initiated a climb to avoid the traffic. I advised Approach of a near miss and our traffic avoidance climb. Approach subsequently vectored us for ILS and landing without any further issues.
A Corporate pilot reported taking evasive action to avoid conflicting traffic which ATC had advised would not be a factor.