Pan American World Airways, originally founded as Pan American Airways and commonly known as Pan Am, 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 jet aircraft, jumbo jets, and computerized reservation systems. Until its dissolution in 1991, Pan Am "epitomized the luxury and glamour of intercontinental travel", and it remains a cultural icon of the 20th century, identified by its blue globe logo ("The Blue Meatball"), the use of the word "Clipper" in its aircraft names and call signs, and the white uniform caps of its pilots.

Founded in 1927 by two former U.S. Army Air Corps majors, Pan Am began as a scheduled airmail and passenger service flying between Key West, Florida, and Havana, Cuba. Under the leadership of American entrepreneur Juan Trippe, in the 1930s the airline purchased a fleet of flying boats and focused its route network on Central and South America, gradually adding transatlantic and transpacific destinations. By the mid-20th century, Pan Am enjoyed a near monopoly on international routes. It led the aircraft industry into the Jet Age by acquiring new jetliners such as the Boeing 707 and Boeing 747. Pan Am's modern fleet allowed it to fly larger numbers of passengers, at a longer range, and with fewer stops than rivals. Its primary hub and flagship terminal was the Worldport at John F. Kennedy International Airport in New York City.During its peak between the late 1950s and early 1970s, Pan Am was world-renowned for its advanced fleet, experienced and highly trained staff, and numerous amenities. In 1970 alone, it flew 11 million passengers to 86 countries, with destinations in every continent save Antarctica. In an era dominated by flag carriers that were wholly or majority-owned by governments, it became the unofficial national carrier of the United States. Pan Am was a founding member of the International Air Transport Association (IATA), the global airline industry association, and helped shape the industry standard in hospitality and customer service.

Beginning in the mid-1970s, Pan Am began facing a series of challenges both internal and external, along with rising competition from the deregulation of the airline industry in 1978. After several attempts at financial restructuring and rebranding throughout the 1980s, Pan Am gradually sold off its assets before declaring bankruptcy in 1991. By the time it ceased operations, the airline's trademark was the second most recognized worldwide, and its loss was felt among travelers and many Americans as signifying the end of the golden age of air travel. Its brand, iconography, and contributions to the industry remain well known in the 21st century. The airline's name and imagery were purchased by railroad holding company Guilford Transportation Industries in 1998, which changed its name to Pan Am Systems and adopted Pan Am's logo.

The Boeing 747 is a large, long-range wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States.

After introducing the 707 in October 1958, Pan Am wanted a jet 2+1⁄2 times its size, to reduce its seat cost by 30% to democratize air travel. 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 its JT9D engine, a high-bypass turbofan. On September 30, 1968, the first 747 was rolled out of the custom-built Everett Plant, the world's largest building by volume. The first flight took place on February 9, 1969, and the 747 was certified in December of that year. It entered service with Pan Am on January 22, 1970. The 747 was the first airplane dubbed "Jumbo Jet", the first wide-body airliner.

The 747 is a quadjet, initially powered by Pratt & Whitney JT9D turbofan engines, then General Electric CF6 and Rolls-Royce RB211 engines for the original variants. With a ten-abreast economy seating, it typically accommodates 366 passengers in three travel classes. It has a pronounced 37.5° wing sweep, allowing a Mach 0.85 (490 kn; 900 km/h) cruise speed, and its heavy weight is supported by four main landing gear legs, each with a four-wheel bogie. The partial double-deck aircraft was designed with a raised cockpit so it could be converted to a freighter airplane by installing a front cargo door, as it was initially thought that it would eventually be superseded by supersonic transports.

Boeing introduced the -200 in 1971, with more powerful engines for a heavier maximum takeoff weight (MTOW) of 833,000 lb (378 t) from the initial 735,000 lb (333 t), for a longer 6,560 nmi (12,150 km) range up from 4,620 nmi (8,560 km). It was shortened for the longer-range 747SP in 1976, and the 747-300 followed in 1983 with a stretched upper deck for up to 400 seats in three classes. The heavier 747-400 with improved RB-211 and CF6 versions, along with the PW4000 (the JT9D successor), and a two-crew glass cockpit, was introduced in 1989 and is the most common variant. After several studies, the stretched 747-8 was launched on November 14, 2005, with new General Electric GEnx engines, and was first delivered in October 2011. The 747 is the basis for several government and military variants, such as the VC-25 (Air Force One), E-4 Emergency Airborne Command Post, Shuttle Carrier Aircraft, and some experimental testbeds such as the YAL-1 and SOFIA airborne observatory.

By June 2020, 1,556 aircraft had been built, with fifteen 747-8s remaining on order. Manufacture of the 747 is scheduled to end in 2022 after a 54-year production run. Initial competition came from the smaller trijet widebodies: the Lockheed L-1011 (introduced in 1972), McDonnell Douglas DC-10 (1971) and later MD-11 (1990). Airbus competed with later variants with the heaviest versions of the A340 until surpassing the 747 in size with the A380, delivered between 2007 and 2021.

As of 2020, 61 Boeing 747s have been lost in accidents, in which a total of 3,722 people have died.