owned. Specifications (4-E) See also References Citations Bibliography External links Stearman 4-EM Senior Speedmail The Stearman 4-D Jr. Speedmail Stearman 4-C ATC Stearman 4-D ATC Stearman 4-E ATC 1930s United States mailplanes 4 Biplanes Single-engined tractor aircraft Aircraft first flown in 1930