Ryan NYP "Spirit of St. Louis" Welded Steel Aileron Frame Inspection (View 1) (1927)

Vertical view of bare welded steel-tube aileron framework resting on wooden crate against workshop wall. — Ryan NYP "Spirit of St. Louis" Welded Steel Aileron Frame Inspection (View 1) (1927) · Donald A. Hall Estate Collection

An archival engineering construction photograph showing the uncovered aileron framework of the Ryan NYP Spirit of St. Louis inside the Ryan workshop. Resting vertically atop a wooden crate, the structure reveals thin-walled chrome-molybdenum steel tubing with internal Warren-truss diagonal rib bracing and central control horn fittings. Donald A. Hall Sr. engineered the control surfaces in welded steel to provide maximum torsional rigidity and eliminate aerodynamic flutter across the aircraft's 46-foot wingspan.