Singapore Changi Airport began operations with one runway and one terminal on July 1, 1981, and in those intervening 43 years, it has welcomed some of the world's most iconic airlines and aircraft and is home to the much-loved Singapore Airlines. For nearly half of the airport's existence, the red tails of AirAsia have been flying in out and out, and yesterday, AirAsia marked 20 years of operation at Singapore Changi Airport (Changi).