Somehow I knew LVT would get in there ;)

Good points though.
The Tories like to paint themselves as pro-free market, but they are Conservatives, and they're generally well named. Despite a period of radicalism (perhaps driven by an ultra-conservative desire to reverse changes?) under Thatcher they are still essentially conservative and don't like to change the status quo much.

Taxing per-flight is a good idea, although surely its best to tax the fuel this throws up problems due to the mainly international nature of the business.

The landing slot anomaly is bizarre and needs sorting. Your solution works well (especially given landing slots appear to be determined by historical legacy rather than anything else).