FIAP, April 28 / PRNewswire-Asianet /-- according to the official account of HNA Group, HNA and Comac signed a framework order agreement for 100 C919 and ARJ21 aircraft in Shanghai on April 27th. In the future, the two sides will also cooperate in the fields of aircraft import and export, aircraft materials maintenance, logistics warehousing, application of new technologies, aircraft materials support, maintenance support, aircraft configuration optimization, and so on.