About

The Boeing 747 is a four-engined widebody jetliner ("Jumbo Jet") produced by boeing. The first-ever widebody (twin-aisle) airliner, it first flew in February 1969 and entered commercial airline service in January 1970. With a maximum passenger capacity of 400 to 660 (depending on the model), it was also the largest and highest-capacity airliner until the airbus-a380 was introduced in 2007.

The 747 was the first jetliner to have a double passenger deck; the lower deck extends the full length of the pressurized cabin, while the upper deck terminates either in front of (most older-series 747s) or above (a few 747s from older series, plus all newer models) the wings, giving the 747 an instantly-recognizable hump in front of the wings. Boeing chose this configuration so that the 747 could be easily converted to a cargo aircraft by adding a cargo door in the nose, as, when they were designing the 747 in the 1960s, it was believed that the long-haul passenger market would soon be taken over by supersonic airliners (such as the concorde and Boeing's own never-built 2707), which were all the rage at the time. Although this did not, for the most part, happen, a large number of 747s have nevertheless been converted to cargo aircraft, and many more came from the factory in cargo configuration. The 747's cockpit is at the front of the upper deck; the space behind the cockpit was used for a passenger lounge in the very first 747s, but was later used by most airlines to add additional (usually first- or business-class) seating.

The 747 was also the first jetliner powered by a high-bypass turbofan engine (a turbofan with a bypass-ratio greater than 5:1), rather than the turbojets or low-bypass turbofans used by previous jetliners (although not the first aircraft overall to use high-bypass turbofans; that honor belongs to Lockheed's C-5 Galaxy military transport).

The 747 has had six major versions over the years:

• The 747-100 was the first 747 to enter service; 206 were built. 168 of these were vanilla -100s, 29 were the higher-passenger-capacity -100SR (Short Range)/-100BSR variant developed especially for the Japanese market, and the remaining nine were long-range 747-100Bs (based on the 747-100SR, but with extra fuel capacity instead of extra passenger capacity). Most 747-100s had the original short upper deck (terminating in front of the wings), but two of the very last -100BSRs (built in 1986) were delivered with the stretched upper deck introduced with the 747-300. One vanilla 747-100 and one 747-100SR were modified by nasa to ferry the space-shuttle from place to place. No 747-100s remain in commercial operation, the last having been retired by Iran Air in 2014.
• The 747-100 had barely enough range for intercontinental flights, leading to the development of the 747-200; introduced in 1971, the -200 has more powerful engines and a greater fuel capacity than the -100, giving it a considerably increased range. Most -200s have the original short upper deck, but some later -200s were sold with the -300-length stretched upper deck. 747-200 production ended in 1991 after 393 had been built. Since Iran Air's retirement of its passenger 747-200s in May 2016, none of the type remain in commercial passenger service; eight -200s are still flying as freighters, while two heavily-modified -200s are operated by the us-air-force under the "Boeing VC-25A" designation as the primary air transport for the president of the United States of America (these aircraft are popularly, though not quite accurately, known as air-force-one).
• The 747SP (Special Performance), a long-range version with a shortened fuselage, was introduced into service in 1976; 44 were built from 1974 through 1982, plus one last 747SP in 1989. It is the smallest and lightest 747, and the first in which the upper deck extends above the wings (the SP has the original short upper deck, but it nevertheless extends over the wings due to the shortening of the forward fuselage). The last 747SP in commercial passenger service, belonging to (again) Iran Air, was retired in 2016, but several continue to fly as government or VIP transports, plus three used by Pratt & Whitney as engine testbeds and one heavily-modified 747SP operated by NASA and the German Aerospace Center as the platform for an airborne infrared telescope (the Stratospheric Observatory for Infrared Astronomy, or SOFIA).
• The 747-300 was introduced into service in 1983, and was the first model of 747 to incorporate the new, stretched upper deck (after the 747SP proved that having the rear portion of the 747's hump extend over the wings would not negatively affect the aircraft's aerodynamics); the stretched upper deck was also later offered as an option on post-1980 747-100s and -200s. Only 81 -300s were produced before production stopped in 1990 (77 of the basic 747-300, of which five remain in service today, plus four high-capacity 747-300SRs for the Japanese market), it having been overtaken after just two years by the 1985 announcement of...
• the 747-400, which entered service in 1989, featuring a larger wing, more efficient engines, and increased fuel capacity, which combine to give it a considerably longer range than any previous 747. Other improvements include a revamped cabin interior and a so-called "glass cockpit" (using electronic displays rather than the traditional sea of mechanical gauges and dials), the latter allowing the -400 to fly with a two-person flight crew, eliminating the need for a flight-engineer. Passenger -400s, and -400s converted from passenger to freight service, have the -300-length upper deck, while those delivered as freighters have the shorter, -100-length upper deck. 694 747-400s of various flavors were built (the most of any 747 version) before the production line shut down in 2009, over 300 of which remain in service.
• The latest version is the boeing-747-8, a stretched version with yet-more-efficient engines that entered service in 2011. The passenger version of the 747-8, the -8I (Intercontinental), became the longest airliner in the world when it was introduced by lufthansa in June 2012, surpassing the airbus-a340. As with the -400, -8s delivered as passenger aircraft have the stretched upper deck, while those delivered as freighters have the short upper deck. As of September 2018, 150 -8s have been ordered and 129 delivered, with about two-thirds being cargo aircraft. Boeing has had great difficulty selling the 747-8I amidst two general trends: one toward smaller jets, and the other toward twinjets (such as the company's own boeing-777 and boeing-787).

For more information, see Wikipedia's articles on:

• the 747
• the 747SP
• the 747-400
• the 747-8