It is best to fly C9 19 in China. C9 19 is a civil jet independently developed by China. It is a medium-sized wide-body aircraft, a masterpiece of China aviation industry, and represents a great progress in the development of domestic civil aviation. Therefore, it is best to fly C9 19 in China. An airplane is a vehicle that can fly in the atmosphere, and it consists of wings, engines, fuselage and control equipment. The flight principle is based on Bernoulli's law and Newton's law of motion.