EMB ERJ 145 ER/LR
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Landed in Emergency Condition; Flight Crew FLC Overrode Automation; General Maintenance Action; General Flight Cancelled / Delayed
Aircraft
While in cruise at 13;000 [feet]; the crew received master warning message 'Autopilot Fail.' I (Pilot Flying) hand flew aircraft and silenced auto pilot disconnect aural annunciation. Shortly after taking manual controls; Caution message 'Yaw Dampener Fail' and Rudder system 1-2 INOP' appeared. I remained Pilot Flying and took over control of radios while Captain ran QRH Checklist. The QRH directed us to push out both Rudder SYS 1 and Rudder SYS 2 buttons on overhead panel. Further along the QRH directed us to PUSH in Rudder SYS 1 and Rudder SYS 2 one at a time. We followed the QRH and PUSHED in Rudder SYS 1 and nothing happened. Captain then PUSHED in Rudder SYS 2 the aircraft started a hard yaw to the right. The Captain immediately pushed the Rudder SYS 2 button back out and yaw stopped and aircraft flew normally. Rudder SYS 2 button remained pushed out and caution message 'Rudder SYS 2 Inop' remained rest of flight. I (Pilot Flying) continued to hand fly aircraft to ZZZ and the Captain continued to notify Company and [advised ATC] and [told] Flight Attendant and passengers. Shortly after [advising ATC] we were cleared to ZZZ via present position Direct. Captain calculated landing performance and speeds with guidance from QRH. We briefed the approach and accomplished all adequate checklists. We received radars vectors from ATC for ILS XXL. Approach was flown and landed without incident. We taxied to gate and wrote up in maintenance logbook.  EICAS messages: 'AUTO PILOT FAIL'; 'YAW DAMPER FAIL' RUDDER SYS 1-2 INOP'
E145 flight crew reported loss of rudder control required a precautionary landing.