On 25 November 2021, a Fokker F50 departing Helsinki experienced an engine malfunction that resulted in an uncommanded propeller feathering. The associated engine continued to run until shutdown, during which time it began to overspeed. The aircraft landed safely, but the failure experienced was untrained, and this led to both direct and indirect consequences that resulted in a suboptimal crew response to the emergency. The Investigation also highlighted opportunities to improve aspects of the air traffic control emergency response during such emergencies and identified language proficiency certification issues.