It's been heralded by some as yet another way of boosting Northern Ireland's business and tourism sectors while helping us compete against our neighbours in the Republic.
But just like corporation tax, bringing an end to air passenger duty (APD) could mean having to pick up the bill if the numbers don't add up.
It could mean a big cut in the block grant the Executive receives from Westminster if scrapping the tax doesn't bring in the passenger numbers.
APD is a tax on flights leaving Northern Ireland. But last year, the Republic dropped their equivalent - paving the way for airports such as Dublin to attract a host of new routes. The move prompted an outcry from business groups and politicians here, concerned about the impact it could have on Northern Ireland's airports. Dublin serves five times more cities than Belfast, with seat capacity in the summer 10 times higher than it is here. And it's that business that Northern Ireland's airports want to attract - whether that be through an end to APD or by some other means.
While Northern Ireland has already binned the tax on long haul flights, unfortunately that only applies to a single direct flight to New York.
But it did save the service, which was facing the axe.
So, the debate now moves to Westminster, which has the ability to bin, or reduce the tax, across the UK.
And yesterday Finance Minister Simon Hamilton said he would "continue to stress" to London that APD is "an unfair tax which has an adverse impact upon travellers departing Northern Ireland's airports".