AirAsia is a low-cost airline based in Kuala Lumpur Intl Airport's budget terminal, in Malaysia. It is widely considered as operating the most successful low-cost model in the world. AirAsia operates an exclusively short-haul narrowbody fleet, including variants of the A320, with a low average fleet age of 5 years. Its frequent flier program is the BIG Loyalty Programme, and it is not a member of any current Alliance. Its long-haul arm is referred to as AirAsia X.