B757 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 150; Flight Crew Total 10082; Flight Crew Type 9235
Distraction
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Executed Go Around / Missed Approach; Flight Crew FLC Overrode Automation
ATC Equipment / Nav Facility / Buildings; Weather
The First Officer (FO) was the pilot flying the ILS 19L into SFO. The weather there was IMC with strong winds at about 30 knots gusting to about 40 knots and rain. He captured the localizer and glide scope for ILS 19L while on the auto pilot. Everything seemed normal till just outside of ROGGE intersection when I notice a yellow line through the glideslope on the [flight computer].I waited a second to see if it was momentary loss of the electronic glide [slope]. As I was just about ready to tell the First Officer I saw the autopilot kicked off. I thought he turned it off; but later I found out it was an uncommanded disconnect. I then saw that I got my glideslope back and the FO was still having some problem with his side.I took over the plane at that moment and notice we were about a dot and a half high on the glide [slope]. I slowly pulled back power and lowered the nose and got to one dot high but I could not get any closer because our target airspeed was 145 knots and because of the gusty winds I could not push the nose down further in fear I can over speed the flaps with the airspeed bouncing around because of the winds.I did see the runway but did a go around at about 1;000ft. ATC did ask us why we went around I told him we were not stable for the approach. Later on while being vectored back for the ILS; I also told ATC that we lost the signal to the glideslope and that coupled with the winds /weather was why we went around. We notice on the radio another aircraft asking about the glide scope it seems that they lost the signal momentaryarily too. We then did a second approach with no loss of glideslope and landed in SFO safely.
[Report narrative contained no additional information.]
During final approach to SFO in weather; the glideslope became intermittent. Flight crew executed a go-around and landed on the second attempt. Other crews commented about the quality of the ILS signal.