These photographs were taken during biplane training flights just before and after the United States entered World War I, in San Diego, Calif., and San Antonio, Texas.

Most of the pictures were taken by the pilot of the second man in a plane, usually the flying instructor; a few of the images were taken by the pilot. All the pictures were taken during flights at training airfields.

As you can see, most of the instructors were no older than the pilots they were guiding.