Aero Flight 311 (AY311), often referred to as the Kvevlax air disaster, was a scheduled domestic passenger flight operated by Aero O/Y (now Finnair) between Kronoby, Finland and Vaasa. The aircraft, a Douglas DC-3C, crashed near Kvevlax  on January 3, 1961, killing all twenty-five people on board. The disaster remains the deadliest civilian aviation accident in the history of Finland. The investigation revealed that both pilots were intoxicated and should not have been flying.