Fly by wire control system

BEFORE BEING SELECTED as the design authority and manufacturer of the Concorde units, Dowty Boulton Paul had obtained considerable experience of electrically signalled control systems on the Tay Viscount aircraft in 1957, this being possibly the first aircraft to be controlled by a fly‐by‐wire system. In addition, multiplex actuator packs controlled by electric signals and operating on a majority voting system were tested in investigating their possibilities for fly‐by‐wire systems. The work on advanced designs of multiplex electro‐hydraulic actuator packs progressed in parallel with the Concorde unit design and at the present moment 15 actuators in three packs are being simultaneously tested in an endurance rig which is scheduled to run for 12,000hr. In addition three quadruplex packs are installed in a Hunter Mk. 12 aircraft at RAE Farnborough for flight trials.