File photo taken on June 19, 2017 shows a Boeing 737 MAX 9 at the 52nd International Paris Air and Space Show in Bourget, France. The United States is grounding all Boeing 737 Max 8 and 9 aircraft, said U.S. President Donald Trump on March 13, 2019. (Photo: Xinhua)

Civil Aviation Administration of China said there is no timetable for Boeing 737 Max 8 to return to service, and will not consider approving its flights until there is a clear investigation outcome from the two accidents associated with the plane.