Boeing opened a new front in the war of words over the A380 programme recently. Having focused previously on the market viability of the ultra-large aircraft, it claimed that the aircraft would be seriously overweight.

Airbus dismisses the claim and says it will be at most 2% overweight.

What is certain is that the European manufacturer has continued its long tradition of technological innovation, some of it designed to deliver weight savings.

Together with enhanced aerodynamic performance, lower airframe weight will translate into reduced demand on the engines, resulting in lower fuel burn, reduced emissions to the atmosphere and lower operating costs, says Airbus.

Airbus is extending the use of carbon fibre reinforced plastic (CFRP) in the A380. It will be the first Airbus aircraft to boast a carbon fibre centre wingbox which translates into a weight saving of one and half tonnes compared to most advanced aluminium alloys.

A monolithic CFRP design has been adopted for the horizontal tailplane and elevators. The material has also been used for the upper deck floor beams and rear pressure bulkhead. The wing skins are made of advanced aluminium alloys while the fixed wing leading edge is made of thermoplastics.

GLARE, an even lighter and more resistant material, is being used for the first time on a civil airliner, following extensive testing. The upper fuselage shell of the aircraft is made from GLARE, a laminate made up of alternating layers of aluminium and glass-fibre reinforced adhesive.

Tests showed GLARE to be superior in terms of fatigue as well as fire and damage resistance. Despite its sophisticated qualities and method of manufacture, GLARE is repaired in the same way as standard aluminium.

All told, about 40% of the aircraft's structure and components will be made from the latest generation of carbon composites and advanced metallic materials.

Another first in a commercial aircraft is the 5,000psi hydraulic systems, more powerful than the traditional 3,000psi systems. Increased pressure translates into smaller piping and components and more weight saving, together with easier maintenance.

Not seen before in either commercial or military aircraft is a dual architecture for the flight control system. It features four independent primary flight control systems with two different configurations. Two use conventional hydraulic actuation systems while the other two feature local electro-hydraulic actuators for control surfaces.

Source: Flight Daily News