Originally Posted by
hi55us
Looks like they are also operating this flight as PEK-BOS-SEA-PEK, effectively offering two different markets one-stop options to/from China. They're not selling tickets on the BOS-SEA segment without an onward connection to China, but would be interesting to fly BOS-SEA on a Chinese airline.
Hainan airlines is not selling SEA-PEK either. It is a pure technical stop to refuel and maybe change crew? With the SEA stop, it is actually quicker to fly via Europe to get to PEK. Of course many passengers still prefer a direct flight staffed with Mandarin speaking crews.