Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 113; Flight Crew Total 3600; Flight Crew Type 113
Human-Machine Interface; Time Pressure; Distraction; Workload; Situational Awareness
Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Airspace Structure; Procedure
Flew Tip Toe Visual 28L. Intercepted ILS using autopilot. Was high on GS; while correcting; Aircraft Y joined 28R. Once centered on [the] ILS we were abeam Aircraft Y. At approximately 1;200 ft MSL Aircraft Y drifted south of course. We had a TCAS TA. We both looked at the Aircraft Y drifting; about that time the TA became an RA. It was a descending RA. I thought I disconnected the autopilot immediately; I did not. I attempted to lower the nose and felt resistance; I immediately disconnected the autopilot correctly and descended complying with the RA. Delay in autopilot disconnect was about 3-5 seconds. Went low on glide slope and ATC issued a low altitude alert. RA ended; Aircraft Y corrected back to [the] localizer and we rejoined the GS to 28L. Approach was stable prior to 500 ft so we continued to a normal landing. We debriefed the event at the gate.
On visual approach (Tip Toe 28L) at approx 11-1;200 feet; we received a TCAS RA due to traffic on visual for 28R overshooting their turn to final. TCAS instructed a climb IMMEDIATELY followed by a descend command. We descended below glide slope which prompted SFO Tower to issue a low altitude alert. We informed them of the intrusion and informed the Tower we were returning to glide slope. We were stable and continued approach for an uneventful landing.
A flight crew conducting a Visual Approach reported parallel runway traffic deviated off course causing them to receive a descending TCAS/RA which resulted in a Low Altitude Alert from the Tower.