With a fleet of six , United is the sole domestic operator of the airplane , which boasts high fuel efficiency due to the light-weight carbon-composite materials used in its wings and fuselage . United Flight 139 from Denver to Tokyo was diverted to Seattle on Tuesday . The unscheduled landing was `` due to an indication of a problem with an oil filter '' 787s returned to service this year after battery troubles grounded them for four months . A Boeing 777 is seen at Seattle-Tacoma International Airport in Seattle, Washington January 31, 2014.
United Flight 139 from Denver to Tokyo was diverted to Seattle on Tuesday . The unscheduled landing was `` due to an indication of a problem with an oil filter '' 787s returned to service this year after battery troubles grounded them for four months . A Boeing 777 is seen at Seattle-Tacoma International Airport in Seattle, Washington January 31, 2014.