 Complete the following phrase:  The airport, formerly named Shuangguisi Airport, opened as an auxiliary military airfield in 1938 during the Second Sino-Japanese WarWorld War II. At the time, its runway was only large enough for small biplanes. It was also where the Republic of China Air Force Polikarpov I-15 fighters of the 5th Pursuit Group were based for aerial defense of the Chengdu area against Imperial Japanese bomber raids; this following the Chinese retreat from Wuhan to Chungking now Chongqing as the new provisional capital in aftermath of the 