Small Aircraft
Air Traffic Control Fully Certified
Communication Breakdown
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Human Factors
I was working on southeast plan; and was holding a few IFR aircraft outside of SJC. At the same time; Aircraft X was inbound to NUQ on the ILS. I cleared the aircraft for the approach to cross ZAPEP at 055. While I was coordinating with another sector for a point-out of my holding aircraft; Aircraft X descended below the MVA. I issued a low altitude alert to the pilot; he responded that he was correcting; and I climbed the aircraft to 051 until established again. The aircraft landed without incident. I actually believe the system worked well in this instance. The aircraft descended below the MVA; the alarm went off; the low altitude alert was issued; and the pilot corrected. I do believe that the descent was a pilot deviation as he indicated correcting immediately. I would have reported this to management at the time; but the culture at this facility is trending to be analytical and punitive; not supporting a safety culture.
NCT TRACON Controller reported that an aircraft on an arrival descended below the sector MVA.