B737-700
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 14.0
Situational Awareness
ATC Issue All Types; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Airspace Structure; Human Factors
Aircraft X was established on a downwind for the ILS Approach. I issued Aircraft X a left turn heading 280 and descend and maintain 4;200 feet. Aircraft X read back the correct heading and altitude. When I cleared Aircraft X for the ILS approach he read back the incorrect altitude of 4;000 feet. That's when I observed Aircraft X descending through 3;600 feet. The low altitude alert on the system did not go off until 3;200 feet. I issued the low altitude alert informing Aircraft X of the MVA (Minimum Vectoring Altitude) of 4;200 feet and altimeter of 29.80. I observed Aircraft X half mile west of the localizer and canceled approach clearance and vectored him back around for the approach. The pilot called the facility and informed the Supervisor he thought the altitude issued was 2;200 feet. The low altitude alert for the system needs to be configured to alert prior to 1;000 feet below the MVA in that area.
ATC reported flight flew through final approach course and descended below their assigned Minimum Vectoring Altitude; ATC Low Altitude Alert did not activate in a timely manner.