Maintenance engineers with China's Air Force were checking the J-11 fighters before their flights at an airport in Tibet on May 19. The maintenance team adapted the fighters, which can now carry R-27 and R-73 air-to-air missiles, and are equipped for flight conditions over the Qinghai-Tibet Plateau. Photo: mil.cnr.cn

Engineers check the J-11 electrical system. Photo: mil.cnr.cn

Engineers load missiles onto the J-11 jet fighter. Photo: mil.cnr.cn

Engineers load missiles onto the J-11 jet fighter. Photo: mil.cnr.cn

Maintenance engineers with China's Air Force were checking the J-11 fighters before their flights at an airport in Tibet on May 19.

Maintenance engineers with China's Air Force were checking the J-11 fighters before their flights at an airport in Tibet on May 19.