Tailwind to Tibet

First published in Sky Fighters, Winter 1948. Reprinted in the collections Night Over The Solomons and The Collected Short Stories of Louis L'Amour - Volume 4: The Adventure Stories.
The year is like 1947. Turk Madden is back in the Far East where he is agreed to fly a young woman and her fiancee to search for her lost brother. He had been slying an "important scientific package" from India over China to occupied Japan when he crashed in the remote regions of China's Kansu Province.