Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 2940; Flight Crew Type 991
ATC Issue All Types; Aircraft Equipment Problem Less Severe
Flight Crew Executed Go Around / Missed Approach
Aircraft
We were cleared for ILS runway 28R [at SFO] and assigned 180 KTS to AXMUL. Before CEPIN; we noticed a TCAS target 2 1/2 miles in front and 800 feet below us. Being IMC; we were concerned about the closure rate. As [we] slowed; ATC told us to maintain 180 KTS to AXMUL. We did. As we broke out of the clouds; we noticed no traffic ahead of us on either 28L or 28R.On [a prior similar approach;] I executed a go-around because of a TCAS RA at 800 feet on runway 28R. When I talked to the Tower [later] that day; he informed me there was no aircraft below us. I would like someone to explain to me why I'm getting ghost targets on runway 28R going into San Francisco. I'm concerned safety is being jeopardized and this matter should be looked into.
Reporter stated he had not heard of the TCAS null bus fault but said it sounds like that is a possible explanation.
B757 Captain reported receiving an apparently false TCAS RA on short final at SFO Runway 28R on two approaches on different days. On the first approach; the Captain executed a go-around.