FILTON, just outside Bristol, is where Britain’s fleet of Concorde supersonic(超音速的)airliners was built. There, something remarkable is being created. Little by little a machine is “printing” a complex titanium bracket (钛合金支架), about the size of a shoe, which normally would have to be cut 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.