Convair CV-240 Family - Design and Development

Design and Development

The design began life in a production requirement by American Airlines for an airliner to replace its Douglas DC-3s. Convair's original design, the unpressurised Model 110 was a twin-engined low-wing monoplane of all-metal construction, with seats for 30 passengers. It was powered by Pratt & Whitney R-2800 Double Wasp radial engines and was fitted with a tricycle landing gear, while the aircraft was fitted with a ventral airstair to aid passenger embarkation. The prototype Model 110, registration NX90653 first flew on July 8, 1946. By this time, American had changed their requirements to require pressurization and deemed the design to be too small. The first prototype was subsequently used by Convair for development work for the 240 series before being broken up in 1947.

To meet the requirements of airlines for a pressurized airliner Convair produced a revised design, the Model 240. This had a longer but thinner fuselage than the Model 110, accommodating 40 passengers in the first pressurized twin-engined airliner. The 240 first flew on March 16, 1947.

The Model 240 was followed into production by the Model 340 that had a longer fuselage, longer span wings and more powerful engines. The 340 first flew on October 5, 1951. In 1954, in an attempt to compete with turboprop-powered airliners like the Vickers Viscount, Convair produced the Model 440 Metropolitan, with more streamlined cowlings and new engine exhausts and improved soundproofing for the cabin. As the "Super 240" evolved into the CV-340 and CV-440 the limit of piston-engine performance was reached and the next developments centered on conversion to turboprop power.