Passengers thinking of booking flights from the UK should book before Wednesday if they want to avoid an imminent cost increase. Air passenger duty (APD) is going up on April 1, making flights more expensive. As the duty forms part of the cost of each airline ticket, carriers say the adjustment is likely to result in higher fares on some routes, Majorca Daily Bulletin reports . The amount of air passenger duty per person depends on several things, including ticket class and how far the country'