The pilot’s unexpected encounter with supercooled liquid droplets (SLD), which resulted in a loss of control due to ice accumulation. Contributing to the accident were: (1) the pilot’s failure to maintain the minimum airspeed for flight in icing conditions, (2) the pilot’s failure to disconnect the autopilot every 10 minutes to check for ice buildup, (3) the overweight airplane, (4) the lack of an SLD forecast product for the state of Alaska, and (5) the Federal Aviation Administration's failure to require weight and balance documentation for each flight in Title 14 Code of Federal Regulations Part 135 single-engine operations.