EMB-505 / Phenom 300
Flight Crew Air Transport Pilot (ATP)
Troubleshooting
Aircraft Equipment Problem Less Severe
Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Landed As Precaution
Aircraft
Yaw damp failed. Dutch roll followed. Descent initiated. Aircraft was stable by 27000ft.Phenom has a severe defect in the Yaw damp system. Numerous electrical malfunctions and loss of GPS will cause the system to fail.
At FL410 autopilot disconnected and AP FAIL; YD FAIL and Ventral Rudder Fail CAS messages appeared on PFDs. Aircraft began dutch roll oscillations. Reduced power to begin descent. Advised ATC need to descend to FL250. Cleared to descend. Spoiler opened to assist in descent and received SPDBRK SW DISAG CAS message so spoiler was switched back to close position and CAS message cleared. Requested diversion to ZZZ. ATC gave left turn ...for the ... arrival to ZZZ. Dutch rolls stopped passing through FL270....
Flight crew of an Embraer Phenom 300 reported a yaw damper failure followed by dutch rolls. Crew descended to a lower altitude and diverted to a nearby airport.