Reader Jon Parent asks,

I am looking to fly [Boston – Fairbanks] on [American] in June. I found availability for [Boston-Anchorage] only at first saver. However, when I search [Anchorage-Fairbanks], I find business availability as well at the perfect time.

I am wondering why [the award search website] doesn’t display all of the segments [to get me from Boston all the way to Fairbanks]. Could it be because the connection time [in Anchorage before connecting on to Fairbanks] would only be about a half hour? Thanks and keep up the good work.

Assuming that your arriving flight and departing flight are on time, there’s a certain minimum amount of time you can expect to take to deplane your arriving aircraft and make it over to your connecting gate to board your next flight.

Different airports have different layouts that are going to cause the minimum amount of time you need between flights to differ.

And if you’re going to have to clear immigration when you arrive, that takes extra time. If you’re going to need to clear security again before making it onto your next flight that takes time too.

All of these particulars have to be taken into account. And each airport has a published minimum connection time.

Generally if you don’t make your connection, such as because of a late arriving flight, if you’re on one ticket then the late arriving airline will be responsible for getting you to your final destination. (Note that American will take care of you even if you are on separate tickets as long as you are arriving from or connecting to a oneworld airline.)

So they’re not going to let you book connections which are shorter than this minimum allowable connection time.

There are also airline-specific minimum connection times that can vary from the standard.

For instance, making an “inline connection” (transferring from and to the same airline) may on some occasions have a shorter minimum connection time, for instance if the airline is all in the same terminal and the terminal is pretty compact.

Making a connection between terminals may have longer minimum connection times.

And in cities where there’s more than one airport there may be published minimum connection times — such as to go from New York LaGuardia to New York JFK (which you’ll be on your own getting between the airports, but it’s not uncommon for people to fly into one and out of the other).

Two paid sources of minimum connection time data are Expertflyer amd the KVS Tool.

Here’s what you’ll see looking up Anchorage at Expertflyer.

Let’s decode.

Transferring from the same (inline) or different (offline) airlines you’ll see that the connecting times are the same. (Note that I’m ignoring here any exceptions that are flight number-specific.)

Connecting between domestic flights in Anchorage requires a minimum 30 minutes between flights. Note that you’re going to land and the onward flight should already be boarding — so you’re going to have to hustle.

Interestingly if you’re connecting to an international flight the published minimum is an hour, even though there’s no immigration to clear.

That same hour will cover you if you are arriving from an international flight (clear immigration and customs, re-clear security) and connecting to either a domestic or an international flight.

That’s a very short window. Many airports require 90 or even 120 minutes connecting from an international flight.