Forgotten Aviator: The Adventures of Royal Leonard, by Barry S. Martin (2011)(**)
He knew and flew with the famous people of his time: Doolittle, Chennault, and Jackie Cochran. He flew the Hump, bombers over China, and was Chiang Kai-shek’s pilot – and there’s much more to tell!
https://www.amazon.com/Forgotten-Aviator-Adventures-Royal-Leonard/dp/1608449297