United Airlines will operate additional flights to Shanghai and Chengdu, China, from the airline's premier trans-Pacific gateway hub in San Francisco, U.S.A, during the peak summer travel season this year.

The current daily service between San Francisco and Shanghai will increase to two flights daily from May, 6 to Oct 24, 2015. The three-times-weekly service between San Francisco and Chengdu will increase to a daily service from Jun, 4 to Sep 1, 2015, both routes are subject to government approval.

"United Airlines has the most extensive trans-Pacific route network of any U.S. airline," said Jake Cefolia, United Airlines vice president for Atlantic and Pacific sales. "These new flights will further strengthen United Airlines' presence in the region and will offer our customers unparalleled choices and convenience when traveling to China this summer."

Flight 891 will depart from San Francisco International Airport at 2:40 pm and arrive at Shanghai Pudong International Airport at 7:00 pm the following day (all times local). On the return, Flight 890 will depart from Shanghai at 9:00 p.m. and arrive in San Francisco at 5:40 pm on the same day. Flight times will be approximately 13 hours, 20 minutes westbound and 11 hours, 40 minutes eastbound.

United will operate the flights with Boeing 777-200 aircrafts, featuring a total of 269 seats - eight flat-bed seats in United Global First, 40 flat-bed seats in United Business First and 221 seats in United Economy, including 104 Economy Plus extra-legroom seats.

The new summer-season service will operate in addition to United's current daily year-round flights between San Francisco and Shanghai.