Abstract:Electrical flight control system(EFCS) has been widely applied in modern civil aircraft and brings benefits such as weight saving, improvement of flying qualities and improved maintenance strategies. EFCS is designed to meet very stringent requirements in terms of safety and availability, in order to satisfy aircraft certification and airline reliability. Fault detection and faulttolerance technology are the key to realize highly dependable EFCS. This paper deals with the industrial practices on fault detection and faulttolerance for civil aircraft, especially the state of the art and experiences from Airbus and Boeing Company. Several detail examples of fault detection and faulttolerance have been introduced. Finally, future trends and challenges for faulttolerance technology are presented.