The Swanson-Freeman SS4 Two Seater
The Swanson-Freeman SS4, two-seater side by side airplane was designed and built by S. Swanson and E. W. Freeman at Vermillion, S. D., and tested Nov. 11, 1923, with remarkable success. The test pilot, Lieut. M. E. Callender of Sioux City, Iowa, who served at Benbrook Field, Ft. Worth, Tex., and advance pursuit instruction at Sau Diego, Calif., took the machine off after a short run, climbed to 2000 ft. and circled over Vermillion for fifteen minutes during which time he executed various maneuvers such as loops, Immelman turns, dives, sharp turns, etc. which the machine performed with extreme facility.