Yes, but wasn't that the reason why all local goverment owned airports were sold off as PLC's so that they could stand on their own two feet and avoid state aid so they could develope to the correct level as and when with commercial standard loans.
You don't often see a UK airport going cap in hand to the government for a loan do you, as they would be told to go away and they don't seem to want to get involved with anything to do with devolution of APD in Scotland and Wales, theres no financial support for UK airports so as all are operating on a level playing field.
Surely if you have a loan then how could it be construde as a tax fiddle by paying it off by using operational profits, the profits after this undertaking would be the true operational profit as paying off a debt is part of the business and tax paid on whatever is left at the end.
By the way, i am not a business man !!