On Feb 13, 5:15*am, Nyal Williams wrote:
We'll need some kind of formula, mathematicians. *Charge for the footprint
of the tow plane, calculate the number of minutes of free flight without
lift (min. sink rate), remainder of flight time for sale -- unless there
is a landout and a trailer comes for retrieval -- subtract that.

Makes one want to hand around the airport just a thermal away.
Nah!

That's all far too complicated.

Airlines want "permission to continue polluting", at a low
incremental
cost on top of their current operations costs.

We want lots of money relative to our current costs.

Both interests are served by simply equating the airframes, and
transferring a nominal amount of money, say £5000 per year.

Does this have much to do with reducing carbon footprints? No,
of course not; but how effective is the rest of the carbon trading
business at that?