Ryan NYP Wing Spar Structural Cross-Section and Stress Analysis Sheet (1927)

Engineering calculation sheet detailing structural cross-section and bending stress formulas for the Ryan NYP wing spar. — Ryan NYP Wing Spar Structural Cross-Section and Stress Analysis Sheet (1927) · Donald A. Hall Estate Collection

An original mathematical calculation sheet from Donald A. Hall Sr.'s master engineering design files for the Ryan NYP Spirit of St. Louis. The document details the structural cross-section geometry of the built-up Sitka spruce wing spar, illustrating flange thickness, web depth, and centerline dimensions. Hall's handwritten calculations derive the cross-sectional area, moment of inertia, section modulus, and allowable fiber stress under ultimate load conditions, proving the structural integrity of the extended 46-foot high-aspect-ratio wing under overload takeoff weights.