STS-134

I've been on these flights enough to know that these routings are consistent. UA always routes 888 (SFO-PEK) on the great circle route, through Russia and then into China, but routes the return flight, UA 889 (PEK-SFO) southeast, then east over Japan, then out over the Pacific.

Check out the routings for UA889:
https://www.flightradar24.com/data/flights/ua889

And for 888 (the inbound):
https://www.flightradar24.com/data/flights/ua888

I always assumed that this was because the eastbound flight wanted to catch the jet stream and use it to speed across the Pacific.

But then I looked up the routing for CA985 (PEK-SFO):
https://www.flightradar24.com/data/flights/ca985

Also, here's HU7989 (PEK-SJC, which is essentially the same routing, given SJC's location just 30 miles from SFO):
https://www.flightradar24.com/data/flights/hu7989

So why are these routings so different? It's not like CA and HU are flying planes of different capabilities than UA. It's not like CA and HU have permission to enter Russian airspace but UA does not -- UA does it consistently on the inbound. If it's to UA's advantage to ride the jet stream, one would think it would be to anyone's advantage to do so, provided that those airlines have permission to enter Japanese airspace. Is that the issue perhaps? CA and HU don't have permission to route over Japan? I highly doubt it, because I know that CA flies to Japan (I even took a CA flight from Japan to PEK once). And it appears that HU also flies to Japan, so I can't think that Japanese permission would even be an issue here.

Sykes

Late edit: Definitely not ETOPS since CA runs a 747 on the route, and it's Air China rather than China Airlines ... I shouldn't post when I'm this tired.


I suspect that ETOPS is the reason.

China Airlines lost it's ETOPS certification in 2011, although it's possible that they have gotten it back since then (I can't find a source since then). It's possible that Hainan never got one at all. In 2013 they didn't have one yet.

STS-134

ETOPS is not applicable to CA (which is Air China, not China Airlines), as they are flying 748s. It isn't applicable to UA either, at least as long as they do that route with the 744s.

NZZO

UA utilizes UPRs - User Preferred Routes - across the Pacific where they are available and when it is advantageous to do so. Many Asian carriers (particularly Chinese carriers) do not, either as a conscious choice or due to flight planning system limitations, and only follow the fixed route network.

CaptainMiles

I suspect it's because Chinese carriers want to maximize used of Chinese airspace and minimize use of foreign airspace. This may have to do either with national security interests (the idea that flying over home land is somehow safer than over foreign land), or with air navigation fees (pay no fees or yuan at home, have to pay hard foreign currency to Russia). You will notice that just about all such Chinese flights, and all those that you mention, pass over ARGUK, which is a waypoint on the China-Russia border at the most northeastern point of China. By going over ARGUK they maximize use of Chinese airspace and minimize use of foreign airspace.

To UA, that may not matter. China or Russia are both equally foreign to UA. In terms of air navigation fees, UA pays both in home currency (USD) anyway. So they would just pick whichever route is more favorable. UA flights typically do not go over ARGUK.

Boo_Radley

Even without UPR, they could still utilize PACOTS tracks, right?