Martin 4-0-4

Martin 4-0-4
Nine Martin 404s of Southern Airways at Atlanta Airport in 1972, being prepared for departure on the morning wave of flights
Role	Short/medium range airliner
Manufacturer	Glenn L. Martin Company
First flight	October 21, 1950
Introduction	1951
Primary users	Eastern Air Lines Trans World Airlines
Produced	1951-1953
Number built	103
Developed from	Martin 2-0-2

The Martin 4-0-4 was an American pressurized passenger airliner built by the Glenn L. Martin Company. In addition to airline use initially in the United States, it was used by the United States Coast Guard and United States Navy as the RM-1G (later as the VC-3A).

When production of the earlier Martin 2-0-2 was stopped due to problems with wing structural failure the company decided to re-wing an improved version (which had already flown as the Martin 3-0-3). The new aircraft was the Martin 4-0-4. It had structural changes to the wings, pressurization and was lengthened slightly to take 40 passengers. Like the earlier 2-0-2, the 4-0-4 was a cantilever monoplane with a standard tail unit (cantilever tailplane and single vertical stabilizer). It had an airstair in the lower tail section for passenger loading and unloading, retractable tricycle landing gear and was powered by two Pratt & Whitney R-2800-CB16 radial piston engines.

First deliveries in 1951 were made to Eastern Air Lines (EAL) which had ordered 60 and Trans World Airlines (TWA) which had ordered 40. 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. In 1969 they were transferred to the United States Navy and were withdrawn from use by 1970. A total of 103 aircraft were built at the Glenn L. Martin factory in Baltimore.

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