Fly-By-Wire Dual-Dual Flight Control Actuation System 981252

This paper presents the basic principle of force synchronization for the active-active (two actuators actuate on the same surface simultaneously) dual actuation system. A novel approach that solves the force fight between the two actuators for the system is also presented. This is accomplished by utilizing an electronic auto-rigging and a pressure flow control valve. The simple system architecture utilizing fewer components make it possible to achieve the goals of low cost, low weight and higher reliability. The low weight and low cost are essential requirements for the smaller commercial aircraft. This dual-dual (two actuators and two control units) system has been developed by Dowty Aerospace Los Angeles and Saab AB jointly. The system is currently implemented on the SAAB-2000 Turboprop aircraft with five years excellent flight record.