A connection is a point in a journey where the passenger leaves one aircraft and boards another. The layover is the time between the first flight reaching its gate and the second leaving its gate. A long layover, usually more than 24 hours on international tickets, is called a stopover and is priced differently; to a status system it is simply two unrelated flights.
The minimum connection time, MCT, is the shortest layover an airport and its airlines consider workable. It depends on the airport, on whether the two flights are domestic or international, on whether the terminals differ, and sometimes on the airline pair. Airlines will not sell a single ticket that breaks it. Two separate tickets have no such protection, which is why self-connecting passengers are the ones who most need a warning.
What changes on the day
A connection that was legal when it was sold can become impossible in an afternoon:
- The inbound flight is late, and the layover shrinks minute for minute.
- The outbound flight moves to another terminal, and the walk becomes a train ride.
- The outbound flight leaves early, which happens more often than passengers expect.
- The inbound flight diverts or is cancelled, and there is no connection left to make.
None of these is a property of one flight. Each is a relationship between two.
In FlightByte
FlightByte reports flights, not journeys. It does not know that two flights are one passenger's connection, and it does not publish MCT values. What it gives you is both halves, kept current:
| You need | Read |
|---|---|
| When the inbound reaches its gate | arrival.bestTimeUtc on the first flight |
| When the outbound leaves its gate | departure.bestTimeUtc on the second |
| Whether the terminals differ | arrival.terminal and departure.terminal |
| Whether either is off the rails | status.cancelled, status.diverted |
The layover right now is the second value minus the first. Subscribe to both flights, recompute on every delivery that touches either time, and compare against a threshold you choose per airport. Missed connection alerts from two subscriptions has the state machine, including the rules that stop it from crying wolf. The three kinds of time behind bestTimeUtc are explained under scheduled, estimated and actual times.