1743. Fifteen Years of Flight Control Evolution on European Airbus Aircraft Weight Impact

Paper

Abstract

Most civil transport aircraft flying today have moving surfaces that are controlled mechanically by hydraulic servomotors. In order to improve aircraft performance these controls have become more and more complicated and have now become a nightmare of complexity from the design and maintenance points of view. Within Airbus Industrie Aerospatiale is responsible for flight control and has developed a new concept: ”Fly-by-wire”. This paper will present the technological evolution of flight controls since the A300-B4 aircraft with mechanical controls, the A310 and A300-bUO with some electrical secondary flight controls, up to the A320 with electric primary pitch and roll controls and the introduction of the side-stick controller. The fifteen years of evolution introduce a direct weight saving of about 30 ~ of the total flight control weight; this weight impact will be examined, dissociating the different functions and mechanical and electrical parts. Other indirect weight benefits appear on the wing structure thanks to load alleviation, or flight deck layout by removal of the conventional control columns. What is important above all is for this weight saving to be accompanied by other benefits of a different nature, such as: improved control surface efficiency, improved safety thanks to protection systems in electronic computers for flight envelope limits, and reduced crew work load. After an initial application on the Concorde supersonic aircraft, fly-by-wire controls have been developed and improved on the Airbus A320, mainly thanks to the progress made in the field of electronic and airborne computers. The future promises considerable evolutions as a result of research on electrical power servo-actuators and fully electric flight controls.