BEIJING: China says its first home-built aircraft carrier has completed five days of sea trials. State media reported Friday the still-unnamed ship completed all assigned tasks before returning to its construction yard in the northern port of Dalian. The 50,000-ton carrier is China’s second and is due to be commissioned before 2020 following the arrival of its air complement. China’s first aircraft carrier, the Liaoning, was bought as a mostly empty hull from Ukraine and was commissioned in 2012. China is seen as striving to supplant the US as the dominant naval power in Asia. It says aircraft carriers are needed to protect its coastline and trade routes, but they are also seen as backing up Beijing’s claims to Taiwan and virtually the entire South China Sea.