What was found
(CAN) 30 MINS OUT, FL260 RUDDER TRIM FAILED, INADVERTENT AND SUDDEN DISPLACEMENT TO HALFWAY TO FULL NOSE LT. DECLARED EMERGENCY, UNEVENTFUL LANDING. RUDDER TRIM FAILED. REMOVED AND REPLACED RUDDER TRIM SWITCH. OPS CHECKS REQUIRED WHEN PANEL REINSTALLED IAW27-12-10, REMOVED AILERON/RUDDER TRIM CONTROL PANEL, REINSTALLED TRIM CONTROL PANEL AND TESTED IAW AMM 27-12-00, CHECKS OK.