Date: 201202
Local time of day: 1801-2400
Location: SFO.Airport, CA
Flight conditions: VMC
Aircraft: Regional Jet 700 ER/LR (CRJ700)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Initial Approach
Airspace: Class E NCT
ATC / advisory: TRACON NCT
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Human factors: Confusion
Anomaly: Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Executed Go Around / Missed Approach
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: While communicating with Norcal Approach; I was the Pilot Monitoring while we were cleared for the Tip Toe Visual approach into SFO; Runway 28L. Once on the heading portion of the published approach; ATC called out traffic on a right downwind which was about to turn right base. After questioning again the position of the aircraft; I called the traffic in sight. I cannot remember whether he said that traffic was for the right or left side; but he said to maintain visual separation with the traffic; follow the traffic; and maintain 210 KTS. I questioned ATC about the speed; since it looked like we were converging quite rapidly; and the communication was blocked. We were coincidentally assigned 180 KTS to the San Mateo bridge by ATC and told to switch to Tower. The First Officer and I were in constant discussion about the close proximity of the aircraft we were following on the right base leg. I felt we were getting entirely too close; and we had not even intercepted the localizer for 28L yet. We then were unsure which runway this aircraft was landing that we were following; and as we were debating a turn off of course to the left to go around; we received a TCAS RA 'descend' command which we complied with for a short time. Once satisfied that we were no in a collision danger; I instructed the First Officer to go around; and climb while turning left away from the traffic. I told Tower of our situation and asked for missed approach instructions; which we complied with. Cause; I believe the aircraft on right base overshot final due to a 30 KTS crosswind from the northwest; blowing him into our center line. We were however confused about which runway he was landing; and had inadequate time to query ATC as the event occurred quickly. ATC in SFO issued 'follow' instructions for aircraft landing the parallel runway; which is extremely confusing; and non-standard. Usually; 'follow' instructions are issued when following an aircraft to the same runway and not the parallel. This even was further complicated by the time of day; which was night time. Suggestions; I believe the other aircraft most likely overshot final; and that we should have been assigned a slower speed so that we were not both turning into each other while turning onto the localizer. Since we never even intercepted the localizer; I see no fault on our part.




Synopsis: Air Carrier inbound to SFO via the Tip Toe to Runway 28L executed a go around when traffic for the parallel runway apparently over flew the final. The reporter expressed concern regarding the ATC term 'follow' which was less than clear.