Ryan NYP Center of Gravity Ground Leveling Test Frontal View (1927)

Frontal head-on view of the Spirit of St. Louis on Dutch Flats field with tail elevated on a stand during center-of-gravity testing. — Ryan NYP Center of Gravity Ground Leveling Test Frontal View (1927) · Donald A. Hall Estate Collection

A vintage positive slide produced from Donald A. Hall Sr.'s original 1927 negative archive, capturing the Ryan NYP Spirit of St. Louis (N-X-211) undergoing ground leveling tests at Dutch Flats, San Diego. Photographed directly head-on, the high-wing monoplane shows its 46-foot wingspan held horizontal while the tail is elevated on an aft test stand to align the thrust line with level flight. Donald Hall utilized this setup to verify aerodynamic symmetry, landing gear track alignment, and the transverse center of gravity prior to initial flight trials.