A319
Communication Breakdown; Confusion; Distraction; Situational Awareness; Time Pressure
Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action; Flight Crew Executed Go Around / Missed Approach
Procedure; Human Factors; Weather
While descending to 2500 feet on the localizer to Rwy 28R (with a good ident); we were told of parallel RJ traffic for 28L and they had us in sight. We got visual on them as well even though visibility was about 3 miles and the runways not in sight. As we continued the approach; the RJ slowly moved toward us and flew directly over us but was about 400 feet above us. It looked like they were also flying the 28R localizer. We asked the Controller to clarify our runway and their runway assignment and they sounded confused but started to move back toward 28L. Since they were on top of us we couldn't go around. So as I decided to break off the approach (hand fly) and turn right because I could see that they were descending on top of us; we got a descend RA. I complied with the RA while the Captain (PM) informed the Controller. Now we were way right of localizer and low so once we were out from under the RJ we performed a go around. We were given vectors around for an uneventful ILS 28L.
The RJ claimed to be maintaining visual with us; however he flew over us and to our right; prior to him correcting his course. All SOP's and checklists were performed.
An air carrier on the SFO 28R localizer took evasive action and executed a go around after another air carrier on the 28L localizer drifted 400 feet over them with no ATC intervention.