Ice in Controls

[pelmet]

I wonder if this is something that can happen, even when a proper control check is completed......

C-GSNR, a Beech 200 aircraft operated by SkyNorth Air was conducting an IFR flight from
Winnipeg/James A. Richardson International Airport (CYWG), MB, to the Island Lake Airport
(CYIV), MB. The first officer was performing the takeoff. During the takeoff roll at 85 Kts, the
aircraft experienced an un-commanded pitch-up, and the aircraft became airborne. The captain
took control with heavy pitch and yaw forces required to maintain control of the aircraft. The
autopilot was switched off but the pilot continued to have difficulty controlling the aircraft. An
emergency was declared and the aircraft returned to CYWG for the RNAV 31 approach with
vectors provided by ATC. Aircraft rescue and firefighting was standing by. The aircraft landed
without further incident.
The aircraft was placed in a heated hangar, and it was noted that water drained out of the elevator.
The operator's maintenance department inspected the flight controls and autopilot system without
finding any faults.

...from TSB.