Martin 404 EasternMartin 404 Eastern Airlines model. The Martin 404 Eastern was designed to meet the growing demand for civil airliners after World War II. Its sleek twin engine design, first flown in 1946, captured the imaginations of all who saw it and quickly entered service in 1947. Originally, the company had planned for a different model, the 3 0 3, but after the loss of a 2 0 2 prototype in 1948, the decision was made to develop the more advanced and safer