The airplane landed safely at about 1228 Eastern time following an in-flight pitch trim malfunction. The airline transport-rated pilot and copilot were not injured and the airplane was not damaged. Visual conditions prevailed.
The flight crew reported a “pitch trim miscompare” message in the cockpit while climbing to FL410. After accomplishing the checklist items and disconnecting the autopilot, considerable forward yoke pressure was required to maintain level flight. The crew found the manual pitch trim control wheel “frozen” in the forward position and were unable to move it. The crew declared an emergency and diverted. Upon reaching 8000 feet msl, the trim wheel released and the system returned to normal. The crew cancelled the emergency and landed uneventfully. Maintenance personnel inspected the flight control system and found the left and right elevator trim actuators contaminated with moisture.