Folding wings have been employed for some military planes on aircraft carriers, but this will be the first instance on a commercial plane.
The upcoming 777X aircraft will sport an extended wingspan of 235 feet, a design change that will bring more flight efficiency but might not fit into how airports are built. The folding wing will allow pilots to reduce the plane's wingspan down to 212 feet, small enough to continue using terminals designed to accommodate older 777 aircraft.
The wing transformation will only work when the plane is on the ground and the FAA developed a special conditions document to ensure that the technology meets safety standards. Engineers developed primary and secondary latch systems that will keep the wings fully extended during flight. Boeing is scheduled to bring the new 777X series to market in 2020.