Date: 201810
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Windshear; Rain; Fog; Turbulence; 4
Light: Night
Aircraft: Caravan Undifferentiated
Operator: Air Carrier
Operating under: Part 135
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Initial Climb
Airspace: Class D ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Autopilot
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Loss Of Aircraft Control
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew FLC Overrode Automation; Flight Crew Landed in Emergency Condition; Flight Crew Regained Aircraft Control
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: I climbed to 500 feet then made a turn to 040. At this time is was told by Tower to contact Center. I now was wings level on a heading of 040 in a climb and had just passed 600 feet. in altitude. I switched to Control and engaged the autopilot. I looked back at my instruments. VIS showed climb; HSI 040; TC had a little right bubble gave it right rudder to correct; airspeed was coming up on 120 KTS; AI looked good but I was getting a little shake.I then key up to check on with Center. 'Center; [aircraft] just off ZZZ at 300 feet climbing to 6;000 feet.' Thats when I said WAITS THATS NOT RIGHT!! I was just climbing to 600 feet and now I'm at 300 feet and my bank angle had increased. I looked at my VSI and it was now showing me in a descent. I looked up out of the cockpit and saw the ground. I disengaged the autopilot and pulled back on the yoke and it was really heavy. I was getting a response from it but it was very heavy and slow. My airspeed was around 100 kts and rising but the yoke was still heavy. At this time I called up Center and [advised ATC]. I told them that I need to get back to ZZZ.They informed me that ZZZ was directly behind me. So I started to make slow turn to the right. Center came back to me saying that ZZZ was straight ahead and I was flying right to it. I informed them that my AI was still showing me in a right turn still. When I took my right hand off the yoke to switch on my synthetic vision on my Foreflight to confirm what Center was seeing. I felt the trim wheel still rotating forward. I grab the yoke again with both hands and again pulling back hard to level the plane out again. It was at this time I reached down and felt for the 'AP CONT' breaker and pulled it out. I got an instant response from the airplane with a nose up pitch. Airspeed started to go down so I pitch nose down slowly until I seen my airspeed start to rise. At this time I put in 30 degrees of flaps and configured the plane for slow flight. It was at this time that I felt like I had control over the plane again. Center informed me that ZZZ1 weather was better and directed me there. I was able to get my synthetic vision up and was using that as my AI. I then asked Center if I was flying a heading 030 they confirmed. I asked 060 they confirmed. They then told me that I was in a slow climb heading 060 and flying straight. I confirmed all this and informed them that my AI was still showing a right turn but that I was using synthetic vision to give me attitude readings. They gave me a heading of 140 direct to ZZZ1. I made a slow turn to that heading. I then took my right hand and hit my AI with the side of my fist and it started to move back to a wings level indication. I told Center what I had done but that I still did not trust it and was going to continue was my digital. When I got ZZZ1 in sight I flew the visual onto Runway XX.




Synopsis: C208 pilot reported autopilot failure; resulting in momentary loss of control and instrument malfunction.