Date: 202108
Local time of day: 1801-2400
Location: ZZZ.TRACON, US
Aircraft: Amateur/Home Built/Experimental
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Descent
Airspace: Class C ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Government
Reporter function: Approach
Human factors: Distraction; Situational Awareness; Workload
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Weather / Turbulence
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Airspace Structure; Company Policy; Human Factors; Procedure
Primary problem: Human Factors

Narrative: Aircraft X had been on radar vectors for the ILS RWY XX approach at ZZZ1. They were on H [Heading]180; and then I turned them left H080; maintain at or above 5;000 feet until established on the localizer; and cleared ILS RWY XX approach. I watched Aircraft X turn towards the localizer; he had a good read back; and was descending out of 067. Shortly after I saw them through the localizer still on H080 and at 052. I advised them they flew through the localizer; and turned them first H030; then H020 to join but quickly realized that they would not turn before the entered an adjacent 060 MVA [Minimum Vectoring Altitude]. I issued a low altitude alert and advised they climb to 060 immediately. When they got to the MVA I vectored them back to the localizer. I asked if the pilot had received the localizer; and he responded affirmative. On the next attempt; I kept them at 060 and asked to report established. They flew through the localizer again; and said they were not receiving it and requested the RNAV RWY XX. I vectored them to final for the RNAV RWY XX; and they were able to establish on final and I cleared them for the approach.Leading up to this event; our facility had just finished working our cargo arrival rush; and traffic had slowed significantly. I was on West Radar; but then got the East Radar controller off position and worked them combined. After a period of about 30 minutes; traffic had built up to moderate levels and moderate-high complexity. This was due to wildfire smoke in the area; and nearly all aircraft being IFR. Our visual separation LOA with ZZZ2 was turned off; and I was staggering approaches between ZZZ2 and ZZZ; and also had a 3 aircraft sequence into the ZZZ1 airport; which has a temporary fire tower in operation. This caused multiple inbound calls via landline for the 3 arrivals. I had a high workload with multiple shout line coordination's from ZZZ3; ZZZ ATCT; and ZZZ2. The FLM was helping with my strips; and another controller came in and after the traffic had slowed a little we split the positions again. It was during this cool down period that the MVA violation happened. The 2 aircraft ahead of Aircraft X both flew the ILS [Runway] XX without issue. When I turned and cleared Aircraft X for the approach; he was in a good position to join final and was descending well; and I remember I was not concerned about them intercepting the localizer.I had been watching my strips print out; and realized it was going to get a little busy but wouldn't be a big deal. However; a military aircraft departed ZZZ2 into the radar pattern; and we got a divert from ZZZ4 to ZZZ1; and some of the coordination's that happened were unforeseen. I just didn't recognize how busy I would become in time to ask for help before traffic became difficult. Of course I will be more diligent in my scan and also recognizing overload situations and ask for help sooner. I think just having Hand-off staffed would have alleviated the overload; and my scan would likely have been better without such a high peak of workload followed by the lull of less traffic. I will also consider vectoring to a longer final and having aircraft join at 060 instead of 050.




Synopsis: A TRACON Controller reported an aircraft instructed to intercept the localizer flew through the localizer twice; once resulting in flight below the Minimum Vectoring Altitude.