There is just no justification for charging handling fees or for that matter landing fees for light aircraft based on a weight formula of a tone or part there of, the cut off points are just too large. Charging by the number of seats or if its apron size that is an issue then by wing span may be more appropriate. It costs exactly the same to handle a AA5A as it does a AA5B, what's the difference, both exactly the same size, and I mean exactly, one 998kg the other 1024kg on which you would be charged twice the amount. Same goes for the TB9 and TB10 and probably many others. With the same number of people on board in these types of aircraft this charging policy can not be justified at all, but then again they don't have to justify it, just rip you off big time.