Background Information.

The Boeing 747 was conceived while air travel was increasing in the 1960s. The era of commercial jet transportation, led by the enormous popularity of the Boeing 707 and Douglas DC-8 had revolutionized long-distance travel. In the early 1960s, even before it lost the CX-HLS contract, Boeing was asked by Juan Trippe, president of Pan American World Airways (Pan Am), one of their most important airline customers, to build a passenger aircraft more than twice the size of the 707.

During this time, airport congestion increased as the number of passengers carried on relatively small aircraft grew, becoming a problem that Trippe thought could be solved by using larger and newer aircraft.

In 1965, Joe Sutter was transferred from Boeing's 737 development team to manage the design studies for the new airliner, already assigned the model number ‘747’. Sutter began a design study with Pan Am and other airlines, to better understand their requirements. At the time, it was widely thought that the 747 would eventually be superseded by a supersonic transport aircraft. Boeing responded by designing the 747 so that it could be adapted easily to carry freight and remain in production even if sales of the passenger version declined. In the freighter role, the clear need was to support the containerised shipping methodologies that were being widely introduced at about the same time.

Standard shipping containers are 8 ft (2.4 m) square at the front (slightly higher due to attachment points) and available in 20 and 40 ft (6.1 and 12 m) lengths. This meant that it would be possible to support a 2-wide 2-high stack of containers two or three ranks deep with a fuselage size similar to the earlier military CX-HLS project.

In April 1966, Pan Am ordered 25 747-100 aircraft for US$525 million. As the launch customer, and because of its early involvement before placing a formal order, Pan Am was able to influence the design and development of the 747 to an extent unmatched by a single airline before or since.

The original design included a full-length double-deck fuselage with eight-across seating and two aisles on the lower deck and seven-across seating and two aisles on the upper deck. However, concern over evacuation routes and limited cargo-carrying capability caused this idea to be scrapped in early 1966 in favour of a wider single deck design. The cockpit was located on a shortened upper deck so that a freight-loading door could be included in the nose cone, this design feature produced the 747's distinctive 'hump'. In early models it was not clear what to do with the small space in the pod behind the cockpit, and this was initially specified as a 'lounge' area with no permanent seating.

A different configuration that was also considered in order to keep the flight deck out of the way for freight loading had the pilots located below the passengers, and was dubbed the 'anteater'.

One of the principal technologies that enabled an aircraft as large as the 747 to be designed was the high-bypass turbofan engine. The engine technology was thought to be capable of delivering double the power of the earlier turbojets while consuming one-third less fuel. General Electric had pioneered the concept but was committed to developing their engine for the C-5 Galaxy and did not enter the commercial market until later. Pratt & Whitney was also working on the same principle and, by late 1966, Boeing, Pan Am and Pratt & Whitney agreed to develop a new engine, designated the JTD9 to power the 747.

The first 747 was rolled out of the Everett assembly building before the world's press and representatives of the 26 airlines that had ordered the airliner on September 30, 1968. Over the following months, preparations were made for the first flight, which took place on February 09, 1969, with test pilots Jack Waddell and Brien Wygle and flight engineer Jess Wallick. Despite a minor problem with one of the flaps, the flight confirmed that the 747 handled extremely well.
During later stages of the flight test program, flutter testing showed that the wings suffered oscillation under certain conditions. This difficulty was partly solved by reducing the stiffness of some wing components. However, a particularly severe high-speed flutter problem was solved only by inserting depleted uranium counterweights as ballast in the outboard engine nacelles of the early 747s.

The flight test program was hampered by problems with the 747's JT9D engines. Difficulties included engine stalls caused by rapid throttle movements and distortion of the turbine casings after a short period of service. The problems delayed 747 deliveries for several months with up to 20 aircraft stranded at the Everett plant awaiting engine installation.

Boeing displayed the 747 to the public for the first time at the 28th Paris Air Show in mid 1969. The 747 received its FAA airworthiness certificate in December 1969, clearing it for introduction into service.

On January 15, 1970, the First Lady of the United States Pat Nixon, christened Pan Am's first 747, at Dulles International Airport, in the presence of Pan Am chairman Najeeb Halaby. Instead of champagne, red, white, and blue water was sprayed on the aircraft. The 747 entered service on January 22, 1970, on Pan Am's New York - London route. The flight had been planned for the evening of January 21, but engine overheating made the original aircraft unusable. Finding a substitute delayed the flight by more than six hours to the following day when ‘Clipper Victor’ was used.

Boeing introduced the 747-200 in 1971, with more powerful engines for a heavier maximum take-off weight 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 B-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 B-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, like the VC-25 (call sign Air Force One) or the E-4 Emergency Airborne Command Post, and some experimental testbeds like the Shuttle Carrier Aircraft.

By June 2019, 1,554 aircraft had been built, with twenty 747-8s remaining on order. As of January 2017, 60 of the jets have been lost in accidents, killing a total of 3,722 people.