Aviation United retrofitting 777s to add more economy seats By Robert Silk / March 09, 2016 Share 1 -- United Airlines will fit an extra seat into the economy rows of approximately a quarter of its widebody Boeing 777 fleet over the next year. The airline began the process of adding a tenth seat across 19 of its 74 777s this month. The first such plane will be put into service in May, United spokeswoman Karen May said. “Ten-abreast 777s are becoming standard in the industry as a whole, so we took that into account,” she said.May said that approximately 50% of Boeing’s 777 deliveries have 10 seats in economy rows, compared with 30% five years ago. American is among the other airlines that uses the 10-wide configuration, the carrier’s website shows. United will convert nine 777 aircraft that it uses on flights between the continental U.S, Hawaii and Guam from an economy configuration of nine-wide to 10-wide. It will do the same with ten planes that are currently deployed for international long-haul routes. After the conversion, those aircraft will be flown on domestic routes, May said. Seats within the 10-abreast economy sections will be 17.05 inches wide, compared with a width 17.3 inches on United’s Boeing 787 aircraft.