This question is prompted by Anthony M..
There’s noting illegal about a ‘legal’ connection.
A legal connection is a term of art that really means a permissible connection.
Each airport has a set amount of connecting time that’s considered necessary to transfer from one flight to another. That time varies based on:
- Whether you are connecting domestic-to-domestic, domestic-to-international, international-to-international, or international-to-domestic. That’s because you may or may not have to go through immigration formalities.
- Whether there’s a change of terminals involved. That may be baked into ‘domestic-to-international’ (where domestic and international flights are in separate terminals) or by exception (because certain airlines mean you’re flying in and out of different terminals.
- The airline and flight you’re connecting to and from. Again, some connections are more arduous than others.
Assuming your flights are on time these connections have been measured out so that under normal circumstances and for most people it should be possible to make it from one flight to another in a standard amount of time.
That’s considered the minimum connection time.
A legal connection is one that gives you at least this minimum connection time between flights.
An airline generally will not sell you a ticket that does not have at least this much time between flights. An online travel agency won’t either. Their systems are updated (usually correctly) to account for the airport, terminal transfer, and airlines that may be involved in your connection.
If you absolutely much ‘force’ a connection that is less than this minimum connecting time, you usually have to do it by buying separate tickets. You can buy whatever you wish separately in most cases, but if you circumvent minimum connecting time and do not make your connection you’re generally on your own without the airline being obligated to help (beyond whatever its standard standby or same-day confirmed policies are for putting you on another flight after you miss yours).
Even if you’re flying the same airline for both segments, and the airline is at fault for you missing the connection, two tickets that do not satisfy minimum connection time guidelines mean the problem is yours and not the airline’s.
There’s no easy way to look up minimum connection times for free.
- You can Google it for a given airport, or given airline. Many airports show minimum connection times on their websites, though this isn’t uniform. Many airlines put standard or average connecting times on theirs, and may also put the actual times for their hubs, on their website.
- Pay service Expertflyer.com shos them.
- So does pay software KVS Tool
If you face a schedule change and your itinerary no longer meets minimum connection times, an airline is going to be obliged to change your flights or refund your tickets.