Beijing's new US$63 billion (S$86 billion) Daxing airport began its first scheduled international flights yesterday as it ramped up operations to help relieve pressure on the city's existing Capital airport. Shaped like a phoenix - though to some observers it is more reminiscent of a starfish - the airport was designed by the late Iraqi-born architect Zaha Hadid, and formally opened in late September, ahead of the Oct 1 celebrations of the 70th anniversary of the People's Republic of China. It boasts four runways and is expected to handle up to 72 million passengers a year by 2025, eventually reaching 100 million. An Air China flight to Bangkok was the first international flight to leave yesterday, while British Airways will operate the first transcontinental flight, to London. About 50 foreign airlines plan to move all or part of their China operations to the airport. The relocation is due to be completed by the winter of 2021. But Air China and its Star Alliance partners will remain mostly at Capital airport. The new airport, roughly the size of 100 football fields and expected to become one of the world's busiest, has come in for some criticism due to its distance from central Beijing.