Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 71; Flight Crew Total 531; Flight Crew Type 145
Troubleshooting; Situational Awareness; Human-Machine Interface
Aircraft Equipment Problem Critical; Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Regained Aircraft Control; Flight Crew Landed As Precaution; Flight Crew Diverted; General Maintenance Action
Aircraft; Human Factors; Weather
Four minutes after takeoff rate of climb decreased from 789 ft/min to 250 ft/min. Airspeed decreased from ground speed of 69 knots to ground speed of 54 knots. Then a loud bang. Plane slid back and rolled to right. Plane dropped 2150 feet in 2 minutes. Was able to level plane at 2200 MSL. Was not able to keep heading. Wings were not stable. Coordinated flight was not possible. Made a complete circle before being able to fly somewhat straight. HSI had tumbled as had the attitude indicator. Asked departure control (NorCal) what was my magnetic heading. Significantly differed from reading on HSI. HSI was not stable. Magnetic compass was not helpful due to roll; and not being able to fly straight and level. Tossed around violently.At some point; someone told the controller to ask if I had autopilot. I answered yes. The person helping the controller told him to have me turn on autopilot and set heading. That was a mistake. The autopilot; within 10 seconds; pitched up to maximum pitch. Pitch warning signal sounded. Red pitch light on; the annunciator turned on. The autopilot could not keep wings level. I managed to disconnect the autopilot; and turned to land towards SNS. I made the decision that I had to land. The controller determined that the closest VMC airport was ZZZ. I flew there with difficulty on maintaining level altitude. Was in IMC most of the flight. Winds were gusting and swirling until I reached 8300 MSL. At ZZZ on the descent; had to deploy 10 degrees of flaps 11 miles out to descend to pattern altitude. Landed safely with wife and dog aboard. Secured plane. Returned with mechanic who did inspection; and then we flew the plane VFR. HSI is being sent for inspection of gyro. Autopilot will be checked completely. Met with flight instructor for an hour to review the flight using flightaware.com and my notes and recollection. When the downdraft dropped and rolled the plane; I was not sure we would make it. She said only thing she would have done differently than I did was to declare an emergency. Weather was changing. Thunderstorms were forecast later in the day. No reports at the time of takeoff. My wife; after we landed; did tell me that off to our right was a dark large cloud. Yet; clouds in front of me had diffuse sun light. All that I know is that after shortly being over the ocean it was like hitting a brick wall. Had latest weather information; but; clearly was insufficient. Not sure how to improve surface and low level weather predictions on the coast.
C182 pilot experienced severe turbulence at 4400 feet during climb to 7000 feet. The airspeed decreased and the aircraft lost controlled flight along with 2000 feet before control was regained. Attitude indicator and HSI were not reliable and ATC provided vectors to a VFR airport.