Introduction
The Boeing 777 FBW system design philosophy [1], [2], [3], results in isolation and separation of redundant flight control elements including Line Replaceable Units (LRUs), ARINC 629 data buses [4] and associated wiring and hydraulic lines to the greatest extent possible. This minimizes the possibility of loss of function due to common-mode or common area faults, and prevents failures of other systems from affecting the FBW operation.