World War II saw a tremendous number of advances in aviation technology. Low-speed maneuverability, robust pressurization systems, and implementation of the first jet engines are just a few of the amazing developments made. Returning GIs, having experienced air travel to distant lands, were expected to fuel a postwar travel boom. That perceived need drove companies such as Consolidated Vultee Airlines (Convair) to propose a new series of medium-range airliners, thus giving birth to the Convair-Liner and their turboprop-powered conversions - the Turbo-Liner. More than 55 years after the first flight of the Convair-Liner, turboprop-powered examples of the type are still hauling cargo in the United States and passengers in a few foreign countries. This book discusses the development of the Convair Twins and their eventual transition from piston power to turboprop power. Over 300 photos illustrate Convair Twins' interior, exterior, powerplants, and systems. Find out who the initial delivery customers of the 240, 340, and 440 were. This book covers the many challenges Convair faced and the technologies employed to advance it. Also covered are military models, domestic and foreign airline operators and models flown, second airline owners, and significant dates in Convair-Liner history.