[nkurz]

Shanghai to Oakland is about 10,000 km: https://www.greatcirclemap.com/?routes=PVG-OAK

Adding a stop in Anchorage adds about 200 km: https://www.greatcirclemap.com/?routes=PVG-ANC-OAK

The plane is probably limited by takeoff weight: body plus fuel plus cargo. By adding a stop in the middle, the plane can take off with less fuel from Shanghai. Since it has 45000 kg less fuel, it can instead carry 45000 kg more cargo. Total fuel consumption for the trip ends up slightly higher, but fuel per kg of useful cargo is much less.

[sdenton4]

Quick, let's build an international air cargo hub on Atka Island!

https://www.google.com/maps/@52.2044509,-174.2639372,10.04z

[edit]: The town of Atka apparently has a population of 53, spread over 32 households. There's an airport, but some expansion would probably be needed to handle Shanghai<->Oakland shipping traffic...

https://en.wikipedia.org/wiki/Atka,_Alaska

https://en.wikipedia.org/wiki/Atka,_Alaska#/media/File:Atka....

https://en.wikipedia.org/wiki/Atka_Airport

[winstonewert]

I'd guess that getting fuel to an island would be much more expensive negating the benefits. (I understand that this was not a serious suggestion anyways).

[konschubert]

I am not so sure, it could come by ship...

[aaron695]

I think that's a brilliant idea. It's only 200km shorter but it takes the longest leg from 7000km -> 5500km https://www.greatcirclemap.com/?routes=PVG-ADK-OAK

I wonder why it has not been done? Maybe because of this -

"In 1996, the U.S. Department of Transportation exempted Alaska's Anchorage International Airport and Fairbanks International Airport from the Jones Act, which prohibits foreign airlines from transporting cargo between U.S. cities. Now, foreign carriers are allowed to refuel their planes in Alaska before continuing on to an American airport or returning home. Because of this, Ted Stevens Anchorage International Airport now handles approximately 80% of all air cargo traffic between Asia and North America."

Maybe you need to find a non American location. A floating refuel location?

It'd be interesting to run the numbers.

[perl4ever]

That is really neat and counterintuitive, because Shanghai and Oakland are 30-something degrees north latitude, and Anchorage is ~60 degrees north, but the stop adds a remakably small distance.

A direct great circle route still goes over the Aleutians, it seems.

[nkurz]

You probably noticed, but in case others didn't, if you click on the "Globe" icon in the upper right for the links I gave it gives a good sense of the Great Circle, and helps make it clear why it's actually an efficient route.

[WalterBright]

> The plane is probably limited by takeoff weight

It is.