Douglas DC-4The Douglas DC-4 is an American four-engined (piston), propeller-driven airliner developed by the Douglas Aircraft Company. Military versions of the plane, the C-54 and R5D, served during World War II, in the Berlin Airlift and into the 1960s. From 1945, many civil airlines operated the DC-4 worldwide. Following proving flights by United Airlines of the DC-4E, it became obvious that the 52-seat airliner was too inefficient and unreliable to operate economically and the partner airlines, American Airlines, Eastern, Pan American, Trans World and United, recommended a lengthy list of changes to the design.
Pan AmPan American World Airways, originally founded as Pan American Airways and commonly known as Pan Am, was an American airline that was the principal and largest international air carrier and unofficial overseas flag carrier of the United States for much of the 20th century. It was the first airline to fly worldwide and pioneered numerous innovations of the modern airline industry, such as jumbo jets and computerized reservation systems.
AirlinerAn airliner is a type of aircraft for transporting passengers and air cargo. Such aircraft are most often operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an airplane intended for carrying multiple passengers or cargo in commercial service. The largest of them are wide-body jets which are also called twin-aisle because they generally have two separate aisles running from the front to the back of the passenger cabin.
Boeing 747The Boeing 747 is a large, long-range wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2023. After introducing the 707 in October 1958, Pan Am wanted a jet times its size, to reduce its seat cost by 30%. In 1965, Joe Sutter left the 737 development program to design the 747, the first twin-aisle airliner. In April 1966, Pan Am ordered 25 Boeing 747-100 aircraft, and in late 1966, Pratt & Whitney agreed to develop the JT9D engine, a high-bypass turbofan.
Boeing 707The Boeing 707 is an American, long-range, narrow-body airliner, the first jetliner developed and produced by Boeing Commercial Airplanes. Developed from the Boeing 367-80 prototype first flown in 1954, the initial first flew on December 20, 1957. Pan American World Airways began regular 707 service on October 26, 1958. With versions produced until 1979, the 707 was a swept wing, quadjet with podded engines. Its larger fuselage cross-section allowed six-abreast economy seating, retained in the later 720, 727, 737, and 757 models.