 THE latest tax increase for air travellers could cost Scottish airports 1.2 million passengers over three years and jeopardise routes, Baa warned yesterday.  a report commissioned by the owner of Edinburgh, Glasgow and aberdeen airports also predicted last November's hike in air passenger duty (aPD) could lose Scotland GBP77 million in tourism. The airports handle 18 million passengers a year.  It is understood that long-haul routes, such as from Edinburgh and Glasgow to New York, could be the most vulnerable.  The fears came amid speculation the UK government might scrap plans to replace aPD with a per-plane tax and increase the tax on short-haul UK flights instead in next month's Budget.  Earlier this week, First Minister alex Salmond called for Scotland to take control of aPD so it could be cut in an effort to increase the number of international flights.  aPD was increased in November by GBP1 to GBP12 for flights from UK airports up to 2,000 miles, and by up to GBP30 to GBP85 for longer routes. Premium class passengers now pay up to GBP170 per flight - an extra GBP60.  The Baa report, by analysts York aviatio 