A cluster of attack helicopters attached to a helicopter regiment of the PLA Air Force airborne units lift off from their parking apron for a tactical flight training exercise on January 17, 2020. Photo:China Military

A cluster of attack helicopters attached to a helicopter regiment of the PLA Air Force airborne units lift off from their parking apron for a tactical flight training exercise on January 17, 2020. Photo:China Military

A cluster of attack helicopters attached to a helicopter regiment of the PLA Air Force airborne units lift off from their parking apron for a tactical flight training exercise on January 17, 2020. Photo:China Military

A cluster of attack helicopters attached to a helicopter regiment of the PLA Air Force airborne units lift off from their parking apron for a tactical flight training exercise on January 17, 2020. Photo:China Military