Showdown negotiations will be held next week between the Airport Authority and Hong Kong-based airlines over the critical issue of landing fees. The authority wants to double the tariff imposed on carriers using the Chek Lap Kok airport. Not surprisingly, airlines are seething and claim they will move non-essential routes from Hong Kong to surrounding airports. Flagship carrier Cathay Pacific has most to lose, with estimates that its return on investment may be halved to a barely sustainable 4 per cent. Cathay reckons fares will have to rise, with the inevitable consequence of reduced passenger numbers. The Airport Authority maintains the proposal to double fees is not a done-deal, but is a necessary evil given the project's targeted 20-year pay-back period. Already the lobbying tactics are clear. The authority is being told to broaden its perspective and consider the greater economic good rather than narrow-minded project financing criteria. The Government should accept a longer pay-back period so Hong Kong can remain an air-traffic hub rather than lose out to competing airports in southern China and Macau. Then again it would be surprising if the airlines didn't kick and scream when asked to pay more. The increased charges will be levied across the board, bringing about the situation where Kong Kong could price itself out of the market as a regional airport hub. Until now, the growth in airline traffic from Hong Kong has been unaffected by the steep fares charged by carriers running duopoly routes to core destinations. Cathay Pacific and other carriers have been given an easy ride by the Kai Tak congestion, which allowed them to operate in a market where demand outstripped the available supply of slots. When Chek Lap Kok opens for business, fare competition should hot up, but passenger volumes will increase. All predictions suggest that the numbers of passengers visiting Hong Kong will rise significantly once the airport's capacity to service them is available. Moreover, airlines will squeeze cost savings from operating in a state-of-the-art airport rather than the antediluvian Kai Tak. Airport Authority negotiators should think twice before bowing to the hollow threats of routes being transferred to other cities. Airlines should be charged what the market will bear.