MU-2 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Commercial; Flight Crew Multiengine
Flight Crew Last 90 Days 20; Flight Crew Total 1900; Flight Crew Type 600
Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Took Evasive Action
Human Factors; Weather
I was on an IFR flight plan to ZZZ descending out of 7000 to 4000 while talking to approach control. It was solid IMC. Tops were 7200; bases were 3800. While descending through 5500 I noted another aircraft on TCAS about 5 miles same altitude traveling toward me also descending. I queried ATC and they said he was a VFR aircraft not talking to ATC. I told ATC it appeared we were closing rapidly; I was given a 30 degree left turn which I immediately performed. The other aircraft at the same time seemed to turn toward me and kept descending. We were within a few miles; I then got a TCAS traffic alert. I started another left turn but the aircraft continued its track toward me. My TCAS showed our aircraft at same altitude and on top of each other on the screen. I then started a climb. I estimate the aircraft passed behind me and we missed by less than 50 feet. I then landed without any other issue. I told ATC that I feel that was real close and I was going to file a NASA report. When I cancelled my IFR on the ground control asked me to call them. I did and spoke to the controller. He verified that there was a loss of separation and that the aircraft was VFR and not talking to ATC. He was able to give me the aircraft type and tail number. I was able to find out who the pilot flying was and I called him to discuss. He said he was VFR; saw a mile wide hole in the clouds and wanted to descend which is when he turned toward me and descended. He said at one point he had me in sight but it was solid IMC. He does not have an instrument rating..
Mitsubishi pilot reported an NMAC with a VFR aircraft while on approach in instrument conditions.