Following the Japanese invasion of China in 1937, Cheung decided to return to China and open a flying school. She toured Chinese American communities and raised money for the venture, securing $7,000. She purchased a Ryan ST-A, but her cousin was killed while testing the plane. Cheung's father, worrying for Katherine's safety, made her promise to give up flying. While she continued for a few years, the loss of her friend Earhart, her cousin, and her father, coupled with her brother's death in China in 1942, finally convinced her to give up flying, as she was then sole support for her mother.
