Filton, just outside Bristol, is where Britain’s fleet of Concorde supersonic airliners was built. In a building near a wind tunnel on the same sprawling site, something even more remarkable is being created. Little by little a machine is “printing” a complex titanium landing-gear bracket, about the size of a shoe, which normally would have to be laboriously hewn from a solid block of metal. Brackets are only the beginning. The researchers at Filton have a much bigger ambition: to print the entire wing of an airliner.