A good ground shot of the Ryan M-2 with an enclosed cabin that was called Bluebird. The photo is assumed taken at San Diego's Dutch Flats airport, very close to, but different from Lindbergh Field which opened in 1928. Photo from: San Diego Air & Space Museum

The Ryan M-2 mailplane was similar to the M-1 except for a new, lighter I-beam wing spar. This particular airframe, however, received a fully enclosed cabin. Finished in light blue dope, it was nicknamed Bluebird. The next development was the Ryan B-1 Brougham. Photo from: San Diego Air & Space Museum