The proposals i've seen are nonlinear. Each person gets, say, one flight a year with no Frequent Flyer Tax. Your second flight is taxed at 100 dollars. Your third, 200 dollars, Your fourth, 300 dollars, etc.

The trick is to pitch it so that you don't have much impact on the 85% of the population who do 30% of the flying, but you strongly discourage the 15% of the population who do 70% of the flying [1]. Partly as a practical measure to ensure it's not so unpopular it gets repealed, but partly because those 15% are probably capable of making changes to their lifestyle or way of working that will drastically cut flights, whereas the other 85% are flying where they have to, to see their family at christmas or whatever, or for their one summer holiday.

You couldn't do that by taxing fuel, or aeroplanes, or anything other than individual people flying.

[1] https://fullfact.org/economy/do-15-people-take-70-flights/

That's a neat idea, but aren't most frequent flyers doing it for business reasons? In which case the business will pay the tab for the tax increase, most likely.

Businesses have a wide latitude to spend on aviation because business travel done right is incredibly lucrative.

The wrinkle I see with escalation of taxes per person per year is while my company would happily pick up the tab for work travel, I’d be upset if my Christmas trip home cost me thousands more because I’d done a handful of business trips.

Then that sounds like escalating taxes would be an extremely effective incentive for behaviour change, despite the fact that employers will be picking up most of the costs!

Or equally likely an extremely effective way to encourage private driving and private flying, both of which are less energy efficient and safe than long-haul airline flights.

Not to mention creating confusion and hassle for travelers, whose ticket price can’t be calculated and paid in advance (because you don’t know how many trips I’ll have taken before that flight), or who share a common name.

one way would be to make it revenue neutral as in take the money from frequent flyers and give it back as tax refund. then people will want more of it.