Is aviation industry Xinghua a state-owned enterprise?

Yes

According to the inquiry of China Daily, Shenyang Xinghua Aviation Electric Appliance Co., Ltd. was established on September 4th 1957 with the approval of the Second Ministry of Machinery Industry. It is one of the key projects during the First Five-Year Plan period 156, belonging to state-owned military units, and the employees who formally enter technical posts belong to the cause series.