Air Traffic Control Fully Certified
Time Pressure; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Procedure; Equipment / Tooling; Human Factors; Aircraft
Aircraft X was IFR at 8;000 5NM W of TALLI intersection. Aircraft X advised that his ACARD went out and came back then went out again. Aircraft X said that he did not need to declare an emergency he just needed to descend to VFR conditions to see what the problem with his equipment was. I descended Aircraft X to 7;000 and then gave him a turn to 320 and continued his descent to 6;000. Aircraft X had some VFR conditions in the area and wanted to continue descent to avoid the clouds. I gave Aircraft X descent to 4;000 and advise me if he needed any other assistance to remain in the VMC conditions during his descent. He then asked to descend to 3;500 and the MVA in the area that was 3;700; I told him about the MVA and descended him to 3;700. I verified that the MVA was at 3;700 and gave Aircraft X the altimeter due to his altitude showing him descending below 3;700 on the scope. Aircraft X responded that he was climbing back up to 3;700 and wanted vectors towards [a nearby] airport. I gave Aircraft X a heading of 150 and maintain 3;700. Position Relieve briefing was started at this time and I gave the next controller all the information about Aircraft X and his intentions to remain in VMC conditions. Before the end of the position relief briefing I gave Aircraft X a heading of 180 and maintain 3;700; vectoring him towards an area with an MVA of 3;400 if he needed to descend anymore. I stayed in the TRACON to see if the next controller needed any assistance with the position.No recommendations to prevent the re-occurrence of this event due to it being an equipment malfunction.
AVP TRACON Controller reported an IFR aircraft with avionics trouble descending below the Minimum Vectoring Altitude.