Non-stop flight time from Los Angeles to Shanghai is around 14 hours 30 minutes. Fastest one-stop flight between Los Angeles and Shanghai takes close to 16 hours . However, some airlines could take as long as 40 hours based on the stopover destination and waiting duration. This is the average non-stop flight time from Los Angeles to either of the major airports that serves Shanghai.
Flagstaff Pulliam Airport (IATA: FLG, ICAO: KFLG, FAA LID: FLG) is five miles south of Flagstaff, in Coconino County, Arizona. The airport is serviced by one airline, American Eagle, and is also used for general aviation.
Flagstaff airport is closer but i dont think many commercial flights go there. The closest majore airport is Phoenix. Even cost wise that is the best. You might find small flights from Phoenix to Sedona or Flagstaff, but its only a couple of hours drive from Phoenix.