March 1950, to support the PLA Army in entering Tibet, PLAAF pilots flew outdated transport planes to the “no-fly zone” over the Kangzang Plateau without a chart or landmark, and blazed out 25 routes by November 1952. They delivered supplies to army troops in Kangding, Ganzi and other places and provided timely assistance for the suppression of insurgencies and national defense construction in Tibet in the early years after it was liberated.