恒天海龙：全资子公司北京多弗海龙飞控科技有限公司从事航空运营支持服务等业务，目前已投入项目研发中

Group 1 - The core point of the article is that Heng Tian Hai Long's subsidiary, Beijing Duo Fu Hai Long Flight Control Technology Co., Ltd., is involved in the aerospace sector, specifically in aviation operation support services [2][3] - The subsidiary is a wholly-owned entity of Heng Tian Hai Long and is currently engaged in project research and development [2]