Ryan NYP Head-On Optical Alignment and Wingspan Calibration View (May 1927)

Direct head-on photograph of the Spirit of St. Louis on Dutch Flats showing full wingspan and landing gear. — Ryan NYP Head-On Optical Alignment and Wingspan Calibration View (May 1927) · Donald A. Hall Estate Collection

A primary engineering photograph capturing a true head-on perspective of the Ryan NYP Spirit of St. Louis on the dirt runway at Dutch Flats. Photographed to confirm transverse symmetry, the image details the full 46-foot wingspan, the high-lift Clark Y airfoil profile, the engine-turned propeller spinner, and the 10-foot wide-track split-axle landing gear. Chief Engineer Donald A. Hall Sr. used these head-on alignment views to verify wing dihedral and rigging tension before flight clearing the aircraft.