Long haul air travel to and from the UK is already "taxed" pretty heavily given the massive fees at LHR.

And yes, taxation is a fairer way of going with something discretionary like air travel or a lot of gasoline use.

Rationing is only appropriate in cases where the issue is shortage of a necessary commodity - ie "everybody needs food, and if you take more than your share of food someone else might starve." This is certainly not the case for food today, or gasoline, or air travel, and it's not likely to start to be in the near future.