09/30/2010. The Glenn L. Martin Company was a major producer of military aircraft during the Second World War and built a wide range of types including the B-26 Marauder, the Mars and Mariner flying boats and, in the 1950s, the B-57 jet bomber based on the English Electric Canberra. Martin's sole venture into airliner manufacture came immediately after the war with the design of the Martin 202. This unpressurised low-wing twin-engined aircraft was a contemporary of the rather more successful Convair 240 and addressed the same need for a DC-3 replacement.

The 202 was a modern all-metal monocoque design with a retractable tricycle undercarriage and it featured a retractable passenger entry stair under the rear fuselage. Power was provided by two 2,400 hp Pratt & Whitney R-2800-CA18 Double Wasp eighteen-cylinder, twin-row, air-cooled radial engines mounted conventionally on the inboard wing sections. Martin's 40-passenger design, referred to as the 'Martin-Liner' became the first post-war twin-engined commercial transport to receive CAA certification.

The first prototype, registered NX93001, was first flown on November 21, 1946, soon followed by the second, registered as NX93002 c/n 9123, and type approval was granted on August 13, 1947. Only 34 examples of the 202 were produced (including 3 prototypes), 4 went to LAN-Chile (Línea Aérea Nacional de Chile, first operator of the type, with which it entered service in October 1947), 2 were sold to LAV (Linea Aeropostal Venezolana) of Venezuela, and easily the major operator with a fleet of 25 was Northwest Airlines in the USA.

The 202 was grounded for a period in 1948 when a structural weakness was discovered in the wings. Thirteen improved aircraft with a strengthened airframe, increased fuel capacity, increased gross weight of 43,000 lb and
R-2800-C816 Double Wasps, were completed for TWA (Trans World Airlines) as 202As. The 202A first flew in July 1950 and entered service on September 1 of that year.

For marketing reasons the model 202 is also known as 2-O-2 (two-O-two).