Learjet 35
Air Traffic Control Fully Certified
Situational Awareness; Workload; Human-Machine Interface
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; 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
I took radar identification of Aircraft X from the Feeder on a 270 degree heading. Once in my airspace I told the aircraft to descend to 5;000 ft. There was a 5;000 foot MVA he was aimed toward. I thought I gave the aircraft 5;000 ft. and heard the read back. I heard a aural alarm and saw the aircraft descending below 5;000 ft. and told him to climb back to 5;000 ft. and issued a low altitude alert; the pilot complied. None; this was during unusual conditions in the area where ZZZ1 was [runway] XX; ZZZ2 [runway] YY and ZZZ3 [runway] YY. This is a very rare configuration where [combined sectors] has more airspace to scan than usual.
TRACON Controller reported an aircraft descended below the MVA.