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 Universal (no F designation) was the first type by the Atlantic Fokker company and lacked the cantilever wing of the European Fokkers, but fulfilled the needs of American aviation companies at the time. Aero Corporation of California was a flying school, workshop and regional distributor of Fokker. NC696 was the fourth Universal to pass through Aero and was used for demonstration and charter flights before delivery to Pacific Air Transport. Standard Airlines, active from late 1927, was a subsidiary of Aero. Photo from: San Diego Air & Space Museum

This early Tri-Motor was the first plane of Maddux Air Lines, bought by Jack Maddux in July 1927. On other photos taken here at Dutch Flats, or Ryan Field, it still wears its initial registration NC3114, so perhaps changes were made here. By 1928, it reportedly wore fleet number 1 on the fuselage. This is the same Tri-Motor that was put on display in Pennsylvania Station in New York City in 1931. It was later sold or given to Henry Ford for his museum, but somehow it has not survived. Photo from: San Diego Air & Space Museum

Also known as the Davis-Douglas Cloudster, this was the first Douglas aircraft, built in 1921 for a transcontinental flight which was aborted. In 1923 it was modified for sightseeing flights. In 1925 it was sold to Ryan Airlines and modified further into a plush airliner by American standards - there were no passenger airlines then in the USA. Their LA - San Diego service was unsuccessful and the aircraft was apparently used for smuggling booze when it crashed in Mexico in December 1926. Photo from: San Diego Air & Space Museum