Hong Kong Airport Express Train. The Airport Express is the quickest route between the airport and Central Hong Kong; taking just 24 minutes-less to Kowloon. The train runs like clockwork at 12-minute intervals, from 05:50 - 00:48, daily.he Airport Express is the quickest route between the airport and Central Hong Kong; taking just 24 minutes-less to Kowloon. The train runs like clockwork at 12-minute intervals, from 05:50 - 00:48, daily.