Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 75; Flight Crew Total 3500; Flight Crew Type 800
Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification
Aircraft
Trim wheel froze in an upward condition at 16;000 feet. Aircraft climbed to 16;300 feet.  Center advised of altitude change; and was advised of troubleshooting in progress.Strong forward pressure was applied to control wheel. Autopilot and trim switches were turned off. Associated circuit breakers were pulled. Power was reduced. Request was granted for descent to 6;000 feet. Approaching descent altitude; trim wheel became operative. Approach and landing were made normally.
C421 Captain reported a frozen elevator trim resulted in the aircraft overshooting an altitude restriction by 300 feet. The flight crew disconnected the autopilot and ATC provided assistance clearing the crew to descend where the trim became operative.