It had an airstair in the lower tail section for passenger boarding and disembarkation, retractable tricycle landing gear and was powered by two Pratt & Whitney R-2800-CB16 radial piston engines.

The only other new aircraft from the production line were delivered to the United States Coast Guard which had ordered two as executive transports with the designation RM-1G later changed to RM-1 and then in 1962 to VC-3A.

[3] Later in their airline career, as they became displaced from the EAL and TWA fleets by turbine-powered aircraft, the 4-0-4s became popular with "second level" operators, known as "local service air carriers" in the U.S. as described and regulated by the federal Civil Aeronautics Board (CAB), with these airlines needing to replace their Douglas DC-3s.

[5] Southern Airways' last 4-0-4 service was flown on 30 April 1978[6] with the air carrier then replacing them with smaller Fairchild Swearingen Metroliner "Metro II" turboprops.

In February 2008 the last airworthy 4-0-4, an ex TWA aircraft, was ferried to the Planes of Fame Museum in Valle, Arizona.