Heroes of the Eastern Skies

Heroes of the Eastern Skies, is a Chinese war drama filmed in Taiwan, R.O.C. and based on the true story of a small group of Chinese flying aces in 1937 at the beginning of the Second Sino-Japanese War, specifically depicting events in the Battle of Shanghai, Battle of Nanking and the Battle of Taierzhuang; the movie was released on 7 July 1977 in commemoration of the 7/7 Incident which sparked the start World War II in Asia.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.