In order to be as light as possible, the first aircraft built at the beginning of the last century were made from wood and canvas. Aircraft with body and wings made from the strong, lightweight aluminium alloy Duralumin and aluminium pistons for the engines were developed in Germany shortly before and during the First World War. The skeleton of the airships was also made from aluminium. After the war, an all-aluminium construction was adopted worldwide. In the Second World War (see defence technology) the USA built 305.000 military aircraft out of aluminium. In the 1950s and 1960s the largest civilian aircraft were also built almost entirely from aluminium. Since the oil crisis of the 1970s, the manufacturers and airlines have strived to achieve fuel or energy savings by using even lighter materials.
About 70 per cent of the structure - that means the body and wings but excludes the interior fittings - of modern aircraft like the Airbus is made from aluminium, about 15 per cent from fibre-reinforced plastics (vertical and horizontal tail, movable wing parts with the exception of the slats) and about 5-10 per cent each from steel and titanium alloys. Aluminium is used mainly in the form of higher strength alloys containing copper, magnesium and zinc (no aluminium is used in the jet engines). For external parts, these alloys are often clad with unalloyed aluminium, which is very corrosion resistant. A selection of the aluminium parts and their method of manufacture:
- For bulkheads, connection nodes (where the frames or braces come together), frames for portholes, parts for the landing gear and wheel rims: profiles produced by extrusion and forgings.
- Wing boxes and wing frames or parts of the skin of the wings and fuselage, including bracings, are milled or etched from thick plates or open-die forgings.
- The body is largely a monocoque construction that is riveted or adhesive bonded.