Is this plane change too short?
 

We are looking to travel to Shanghai this fall. Ticket prices have been far above what we usually pay but I've found one flight that's on a par with what we have paid in the past. The problem is the timing is bad.

The first hop lands in SFO at 7:40am. The next flight, a different plane, leaves at 8:30. Both flights are Air Canada although the first is actually UA metal.

There's no way to get into SFO earlier other than by arriving in the previous evening.

What I'm worried about is fog in SFO delaying our flight. On a flight into SFO a few years back we boarded an hour late because of fog--they knew they weren't going to be able to land on schedule and figured it was better for us to sit in the departure lounge rather than making circles in the sky. That time we managed to make our connection but the second flight had already called boarding before we even landed. The shuttle bus taking us to the international terminal was taking passengers by flight time rather than by the order of arrival--and we were in the third load.

This flight is $100 cheaper than anything else we have been able to find.

UA uses Terminal 3, while AC uses Terminal 1. You'll need to take the AirTrain over, and reclear security. 50 minutes will be tight.

But if you miss your connection UA/AC will find a way to get you to Shanghai. Maybe the same day, may be the next. If this is a leisure trip and if AC allows this connection, then the $100 may be worth it. But if you have a job interview or important contract to sign, then no...

Although my crystal ball is not currently operative, fog is mostly a summer phenomenon in the Bay Area. It's much less common in the fall.

Your flight could of course still be delayed for weather or any other reason, and the 50 minute domestic-to-international connection is quite tight. I assume that you're buying this on a single ticket, so it must satisfy the "legal" minimum connecting time. If so, they will take care of getting you onto an alternate connection if necessary. You should definitely not purchase this connection on two separate tickets.

I have several thoughts on your situation:

1) AC via YVR to PEK is very unpleasent IMO because YVR has long lines and those 767s are slow, old, and cramped.
2) You might try routing via YYZ instead. You'll save a lot of time and ride on a newer Airbus. I've heard that YYZ-PEK has been pretty full during the summer, but would guess that things will calm down in the fall. The fact that it only flies several times a week may have kept it off of your radar. It would be worth your while to inquire further.
3) Fall fares are typically a lot cheaper than summer fares, but since it is still summer, I haven't noticed a big drop off..... yet.
4) I just priced BOS-PEK last week for August travel and got quotes for around $1000 on both UA and NW (I ended up going with UA on a different routing).
5) I suggest you wait till the end of the month before jumping on anything. Based on the flights I usually take (mostly UA SFO-PVG), loads have been light this summer. Therefore, I don't think availability should be much of a problem, if you are flexible. In other words, as long as you're reasonably sure that cheaper inventories (e.g. q and v on UA) will be available around your ideal dates, there is no advantage to booking now, assuming fall fares are less than or equal to summer fares.

It's leisure. Other than losing the time it's no big deal.

Are you sure about where AC leaves from? It's an international flight, I thought all of those left from the international terminal. UA runs a shuttle from terminal 3 to the international terminal inside security.

Having to reclear security doesn't sound too makeable.

I'm afraid I don't know YVR.

I don't know where YYZ is, either.

Incidently, we're going to Shanghai (PVG), not Beijing.

We are quite flexible. This is actually 2 weeks later than what we would consider ideal. We want to miss the celebrations in early October and then the later we go the colder it gets but we have no other time issues.

It's on SFO's website: flysfo.com

There's no reason for AC to use the international terminal, as flights from most major Canadian cities are pre-cleared at those origins. Passengers have technically entered the US prior to take off, so those flights can arrive at a US domestic terminal.

And departure of flights from any US airport is the same, whether they fly to international or domestic destination...

Vancouver

Toronto

TMK AC has been flying 330s YVR-SHA for the past month or so, but may switch back to 767s again soon. BOS-YYZ-PEK-SHA is still better than BOS-SFO-YVR-PVG imo, especially if you stop in Beijing (October is best month to visit IMO).

That's good. You should have little to worry about then.