Terneplate Fuel Tank Baffles (1927)

A close-up view of the internal terneplate soft metal baffles and structural rings inside the massive fuel tank of the Spirit of St. Louis. — Terneplate Fuel Tank Baffles (1927) · Donald A. Hall Estate Collection

To prevent the massive load of highly volatile aviation fuel from shifting and destabilizing the aircraft, Donald A. Hall Sr. engineered these internal baffles from terneplate soft metal. This 1927 photograph highlights the invisible, life-saving engineering hidden inside the fuselage of the Spirit of St. Louis.