Hard anodising of aerospace aluminium alloys

During the twentieth century, aluminium became an essential metal in the aircraft industry. Beginning with the cylinder block of the engine that powered the Wright brother's plane at Kitty Hawk in 1903, which was a one-piece casting in an aluminium alloy containing 8% copper, the use of aluminium has grown. In this article, because some reference to US military specifications and industry association guides is made, both US and equivalent metric units will be used together. In 1907 aluminium was used in propeller blades. In 1908 aluminium parts were used in control mechanisms of aircraft. Aluminium covers, seats, cowlings, cast brackets and similar parts were common by the beginning of the the First World War. In 1916, a reconnaissance bomber was developed that used aluminium in the working structure