A319
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Confusion; Communication Breakdown
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance
Flight Crew Became Reoriented
Human Factors; Procedure
We were cleared to heading 090 and descend we complied and proceeded to that heading and the given altitude. After several minutes we were ask[ed] if we had traffic at our 1 o'clock to our 2 o'clock position. As the non-flying pilot and the first officer I located an aircraft at our 1 o'clock to 2 o'clock position and advised we had the traffic in sight. We were cleared to follow the RJ for the visual. We were roughly 4-5 miles from that aircraft. We responded by saying we are cleared to follow visual number 2 when in fact we were number 3 and still was not told of the 2nd aircraft. We spaced ourselves appropriately for a visual to follow the aircraft we assumed to be our traffic. Since no other comment had been made about 2 aircraft. We were advised that our traffic had slowed to 180 which we had already done. Still not knowing about the aircraft or looking for him. ATC then asked if we had traffic at our 12 o'clock position at which time we spotted the 'crj' and turned to heading 120 to extend our downwind squaring off our turn to final and following in for approach. During that verbal exchange I clarified that now we are cleared number 3. We never received an RA during the entire approach. The ops manager that we spoke too insinuated that it would be hard to mistake an RJ from a 737. And when talking about a CRJ or Embraer 145 he would be correct; but an Embraer 175 looks very similar especially from 5 miles away. That is also an 'RJ' that [carrier] flies. We were told to follow the RJ at our 2 o'clock position from the information we were provided we thought we were doing just that. We did not realize there was a second aircraft behind the one we had visual contact with at our 1 to 2 o'clock. If we would have been told that there was yet another aircraft we would have known to follow the second aircraft. This was just a miscommunication.
[Report narrative contained no additional information.]
A319 flight crew reported confusion as to which aircraft they were instructed to follow to the airport. ATC contributed to the ambiguity.