Then how do the airlines want to provide flexibility?

By allowing passengers to change their bookings in advance rather than by turning up for a different flight, and by being flexible with capacity to ensure seats are available rather than having passengers on standby.

The passenger loads of a flight can go down only until the previous flight has left…

That’s true, but don’t forget that shorthaul flights are usually round trip catered from base, and on a high frequency route it is quite likely that by the time a passenger turns up for the earlier flight, the later flight will already have left base, naturally making it too late to change catering figures or crewing levels.

Don’t over analyse what I am saying, these sort of things aren’t a disaster for the airlines as they are very good at pre-empting such changes, and they allow for them in catering figures and so on. It’s just a good example of how getting such things right can be a challenge.

1L