Airbus has announced plans to test folding wing technology for the next generation of its bestselling single-aisle aircraft, revealing the development at the Farnborough Airshow (a major biennial industry gathering south-west of London). The company will fit four-to-five-metre extensions onto an A321neo — part of the A320 family, the bestselling aircraft line of all time — in the second half of next year, exploring how longer, lighter composite wings can improve fuel efficiency while still fitting within the constrained gate infrastructure of airports worldwide. Airbus aims to finalise the design of its next-generation aircraft by 2030, a decision that could also determine engine suppliers, with British manufacturer Rolls-Royce lobbying hard to compete for the lucrative narrowbody engine contract.