Date: 201911
Local time of day: 1201-1800
Location: ZZZ.TRACON, US
Flight conditions: IMC
Aircraft: Skyhawk 172/Cutlass 172
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Final Approach
ATC / advisory: TRACON ZZZ
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Developmental
Human factors: Communication Breakdown
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; 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 Provided Assistance; Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Contributing factors: Weather; Human Factors
Primary problem: Human Factors

Narrative: Aircraft X checked on at 3;600 feet; assigned 4;000 feet asking for 3;000 feet and indicated he did not have the weather and requested it. I gave the aircraft a decent to 3;000 feet and the weather at ZZZ; his arrival airport as well as a base report at ZZZ1 nearby. He then asked what my MVA was in the area; saying he had intermittent ground contact and wished to decent. I explained the MVA was 3;000 feet in his area and to maintain 3;000 feet. At this time he mentioned the possibility of a contact approach at ZZZ. After a few miles I gave the aircraft a vector to miss a 3;200 feet MVA ahead. The pilot then asked for the weather at ZZZ2. After giving the pilot the weather he requested the ILS 20 approach at ZZZ2. I cleared the aircraft to ZZZ2 airport; gave him a vector for the approach and restated his altitude to maintain 3;000 feet along with his mode C readout of 2;700 feet. While trying to coordinate with ZZZ2 Tower; the pilot called back and requested a contact approach to ZZZ2. I cleared the pilot for the approach and coordinated with Tower; then switched the pilot to the Tower. While the pilot was in the downwind for Runway XX at ZZZ2; he decided to turn towards ZZZ airport; his original destination. ZZZ2 Tower called to notify me what he was doing and verified the pilot did not cancel IFR. I called the Supervisor over before the pilot checked back on and explained what was going on. The pilot checked on at 1;700 feet stating he was going to ZZZ and had visual with ground. I asked if he was able to maintain his own terrain and obstruction clearance through 3;000 feet which he said he could. I then cleared him to ZZZ. Meanwhile the Supervisor said he was requesting priority handling for the pilot. When the pilot was about two miles from the field he declared VBT in sight. After a brief discussion; we decided it was in the best interest of safety to clear the pilot for a visual approach even though he was below the MVA and field was reporting IFR conditions; instead of having the pilot climb into IMC and shoot an approach. On final approach the pilot canceled IFR. The Supervisor called the FBO on the field requesting the pilot call the facility to discuss his decision making. The pilot's attitude indicated he was adamant about staying low and it appeared he did not want to execute an instrument approach. It is possible that the tower controller at ZZZ2 could have explained to the pilot that he can't decide he's going to go to ZZZ without a clearance. With that said; the ceilings were less than 800 feet AGL and it would not be safe to have the discussion and coordination with aircraft so low to the ground.




Synopsis: TRACON Developmental reported an IFR C172 pilot failed to comply with ATC instruction; causing the aircraft to descend below the MVA.