O'Hare MCT International to Domestic
 

The O'Hare website claims that the MCT is 40 minutes.

My wife has a transfer from a BA flight to a United domestic next year: Covid permitting. The BA flight is scheduled tol arrive at 1845L with the departure at 2105L, so 2 hrs 20 mins.

When we last transitted, that time through EWR, we had 2hrs 42 mins to transfer, assuming everything was on schedule, but that was United to United.

Even so we still had time enough to visit the Polaris lounge at EWR.

My wife holds a US visa.

In your experience is 2:20 sufficent time? She is travelling in F with carry on only.

Do you have a link to that 40 min. MCT? That seems way too short and from what I see on ExpertFlyer, the MCT (I to D) is 1:30. Regardless, the 2:20 your wife has is sufficient, especially since the inbound rush from most other Europe flights is much earlier than that later BA flight.

The 0:40 DD connection is only for some specific UA-UA connections. EF has the correct default ID MCT (90 minutes). As long as the BA flight is more or less on time, there should be no issue.

When the OP's wife clears immigration and customs, she will need to use the UA check in desks before she clears the sterile area. She can check her bags and get her onward boarding pass. It will make the transit a lot easier. She will be able to go directly to TSA security when she arrives at T3.

Since the arriving flight is on BA, I suspect she will be on separate tickets for her international flight as opposed to her domestic connection.

OP has incorrect information. The MCT for ORD for I-D BA-UA is 90 minutes. That is simply the "legal" minimum at which BA will accept a passenger for a connection -- thus a single ticket -- to UA. If the passenger is traveling on separate tickets, MCT is irrelevant.

If this is on a single ticket, 2:20 is plenty of time and the passenger will be rebooked by BA if it delivers her late to ORD. If on separate tickets, I generally advise no less than 3 times the MCT as a rule of thumb because missing the UA flight will mean that the ticket (and any onwards or return segments on that ticket) will be cancelled and will retain whatever value they retain under the fare rules (generally nothing). This would mean purchasing a new ticket.

Thus, all a risk tolerance assessment.

Doesn't UA have a semi-official flat tire rule to cover missed flights? I wouldn't automatically assume she wouldn't be accommodated.

If the BA flight is going to be late then it's likely that's known before leaving LHR in which the problem can be dealt with up front, including being put on the earlier BA flight or an AA flight to ORD.

OP said she'll have carry-on luggage only. UA is in T1.

You are right about T3/T1.

If OP is on a single ticket, BA will rebook him. I doubt that UA would accommodate across separate tickets as that is the essence of single vs. multiple tickets. I certainly would not take that risk by bookings so close and then hoping.

If the T5 to T3/T1 shuttle bus is back in service when the itinerary is taking place, OP may be able to use that service.
I believe a boarding pass for the UA domestic flight would be required to be in hand. Clearing security at T5 at that time
of the evening is likely to be quick and less of a risk than back at T1. But bus schedule, even if running, might be a factor,
as it wasn't all that frequent.

https://www.flychicago.com/ohare/Ser...Pages/ATS.aspx

https://www.flyertalk.com/forum/amer...3A40%20minutes.

That Wiki is very poorly written so I can see why it caused you to think it's 40 minutes. That amount of time is the minimum for AA if the flights are in the same terminal. In this case, "international" would refer to flights on AA, JA, and IB (not sure if there's another). A connection to T5 necessitates a longer connection... I think they reference 1:15.

In either of those cases, this is for connection off of a domestic or Canada inbound flight and not one requiring immigration at T5.

Thank you all for your advice: my wife is a former flight attendant, hence well travelled. We shall take our chances.