Boeing 747

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Singapore Airlines Boeing 747-412.
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Singapore Airlines Boeing 747-412.

The Boeing 747, commonly nicknamed as the Jumbo Jet, is the most recognized of all modern airliners, and is the largest passenger airliner in service. It will be surpassed in size, however, when the Airbus A380 enters service in late 2006. However, the Antonov An-225 retains the record of being the world's largest commercial aircraft.

The four-engine 747, produced by Boeing Commercial Airplanes, uses a two-deck configuration, where the small upper deck is usually used for business-class passengers. A typical three-class layout accommodates about 400 passengers while a one-class layout accommodates a maximum of 600 passengers. The hump created by the upper deck has made the 747 a highly recognizable icon of air travel.

The 747 flies at high-subsonic speeds (typically 0.85 Mach or 565 mph or 909 km/h) and features intercontinental range (8,430 statute miles, or 13,570 km, for the 747-400 version). In some configurations this is sufficient to fly non-stop from New York to Hong Kong — a third of the way around the globe. In 1989, a Qantas 747-400 flew non-stop from London to Sydney, a distance of 11,185 miles (18,000 km), in 20 hours and 9 minutes, although this was a delivery flight with no passengers or freight aboard.

By May 2005, a total of 1382 aircraft have been built or ordered in various 747 configurations, making it a profitable product for Boeing [1].

Contents

History

The prototype 747, "City of Everett", at the Museum of Flight in Seattle, Washington
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The prototype 747, "City of Everett", at the Museum of Flight in Seattle, Washington

The 747 was born from the explosion of air travel in the 1960s. The era of commercial jet transportation, led by the enormous popularity of the Boeing 707, had revolutionized long distance travel and made possible the concept of the "global village." Boeing had already developed a study for a very large airplane while bidding on a US military contract for a huge airlifter. Boeing lost the contract to Lockheed's C-5 Galaxy but came under pressure from its most loyal airline customer, Pan Am, to develop a giant passenger plane that would be over twice the size of the 707. In 1966 Boeing proposed a preliminary configuration for the airliner, to be called the 747. Pan Am ordered 25 of the initial 100 series. The original design was a full-length double-decker fuselage. Issues with evacuation routes caused this idea to be scrapped in favor of a wide-body design.

At the time, it was widely thought that the 747 would be replaced in the future with an SST (supersonic transport) design. In a shrewd move, Boeing designed the 747 so that it could easily be adapted to carry freight. Boeing knew that if and when sales of the passenger version dried up, the plane could remain in production as a cargo aircraft. The cockpit was moved to a shortened upper deck so that a nose cone loading door could be included, thus creating the 747's distinctive "bulge". The supersonic transports, including the Concorde and Boeing's never-produced SST, never lived up to expectations, such planes being too expensive to operate profitably at a time when fuel prices were soaring.

The 747's upper deck was initially used as a luxurious first-class lounge/bar area. Now, however, the upper deck is most often used for extra seating capacity.

The 747 was expected to become obsolete after sales of 400 units. But the 747 outlived many of its critics and production passed the 1,000 mark in 1993. The expected slow-down in sales of the passenger version in favour of the freighter model has only been realized in the early 2000s.

The development of the 747 was a huge undertaking. Boeing did not have a facility large enough to assemble the giant aircraft, so the company built an all-new assembly building near Everett, Washington. The factory is the largest building ever built.

Pratt and Whitney developed a massive high-bypass turbofan engine, the JT9D, which was initially used exclusively with the 747. To appease concerns about the safety and flyability of such a massive aircraft, the 747 was designed with four backup hydraulic systems, split control surfaces, multiple structural redundancy, and sophisticated flaps that allowed it to use standard-length runways.

Initially, many airlines regarded the 747 with skepticism. Boeing's rivals, McDonnell Douglas and Lockheed, were working on wide-body three-engine "tri-jets", which were significantly smaller than the proposed 747. Many airlines believed the 747 would prove too large for an average long distance flight, investing instead in tri-jets. There were also concerns that the 747 would not be compatible with existing airport infrastructure.

Another issue raised by the airlines was fuel efficiency. A three-engine airliner burns significantly less fuel per flight than a four-engine, and with airlines trying to lower costs, fuel efficiency was an important issue that would briefly return to haunt Boeing in the 1970s.

Boeing had promised to deliver the 747 to Pan Am by 1970, meaning that it had less than four years to develop, build and test the airplane. Work progressed at such a breakneck pace that all those who worked on the development of the 747 were given the nickname "The Incredibles". The massive cost of developing the 747 and building the Everett factory meant that Boeing had gambled its very existence on the 747's success, and the company was nearly bankrupted in the early 1970s.

The gamble paid off, however, and Boeing enjoyed a monopoly on very large passenger transports that would only be broken more than 35 years later with the advent of the Airbus A380.

Variants

The 747 exists as several models, to address the specific needs of its numerous customers:

747-100

747-100 in livery of launch customer Pan Am
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747-100 in livery of launch customer Pan Am

The first model of the jet, the 747-100, rolled out of the new Everett facility on 2 September 1968. The prototype, named "City of Everett", first flew on 9 February 1969, and on 1 January 1970 the 747-100 entered service with launch customer Pan American World Airways. It was later replaced by the 747-100B, a very similar aircraft with a stronger airframe and undercarriage design. The basic 100 has a range of about 4,500 miles (7,200 km) with full load.

Boeing also developed the 747-SR as a 'Short Range' variant of the -100. The SR has a lower fuel capacity, but can carry more passengers--up to 498 passengers in early versions and 550 passengers in later models. This aircraft was primarily used on domestic flights in Japan, but one 747-SR46 (N911NA) is currently being operated by NASA as a Space Shuttle Carrier Aircraft.

The very first 747-100s off the line were built with three upper-deck windows to accommodate upstairs lounge areas. A little later, as airlines began to use the upper-deck for premium passenger seating instead of lounge space, Boeing offered a ten window upper deck as an option, and it quickly became the standard. Some 100s were even retrofitted with the new configuration. A few -100SRs serving with Japan Airlines had their upper decks stretched to accommodate more passengers. This is known as the stretched upper-deck or "SUD" modification.

747-200

Introduced in 1971, and further improved over successive years, the 747-200 had more powerful engines and higher takeoff weights than the -100, allowing it to fly further. A few early build -200s retained the three window configuration of the -100, but most were built with a ten window configuration. As on the -100, a stretched upper deck modification was offered much later. KLM remains the only airline to retrofit their -200s with the SUD option. The last models of the 200, built in the late 1980s, have a full load range of about 6,700 miles (10,800 km).

The 747-200C and 200F variants were designed to carry air freight. The 747-200F is a pure freighter, while the 747-200C is a "convertible" aircraft that can carry either passengers or freight. A sub-variant is unofficially called the 747-200M and is a "combi" aircraft that can carry both at the same time. Like the 100, many 200s have been given a new lease on life as freight aircraft.

747SP

747SP refitted as the SOFIA astronomical observatory
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747SP refitted as the SOFIA astronomical observatory

The 747SP, or "Special Performance," was first delivered in 1976. The SP was largely a stop-gap model to compete with the McDonnell Douglas DC-10 and Lockheed L-1011. The 747 was simply too big for many routes, and Boeing did not have a mid-sized widebody to compete in the segment of the market that the DC-10 and L-1011 had created. Crippled by the huge costs it had incurred in developing both the 737 and 747 in the late 1960s, Boeing could not afford to develop an all-new design, so instead it shortened the 747 and re-optimized it for speed and range at the expense of capacity.

Apart from having a shorter fuselage, the 747SP differs from other 747 variants in having a larger tail surface and larger single-piece flaps on the trailing edges (other 747s use triple flaps). The SP could typically only accommodate 220 passengers in a 3-class cabin, but could fly over 6,500 miles (10,500 km) at speeds of up to 610 mph (980 km/h). Some airline insiders call it the "74 Short" or "Baby Jumbo" because of its shortened fuselage, and stubby appearance. Originally designated 747SB (standing for Short Body), by Boeing, the airlines had Boeing change the production designation to 747SP.

The 747SP was the longest-range airliner available until the Airbus A340, and found its way into the fleets of American Airlines and Pan Am, airlines that needed its range for trans-South Pacific routes (American later used its 747SPs for services to Tokyo), and Iran Air that used it heavily on the daily direct Tehran-New York flight (at the time, the longest-range non-stop scheduled commercial service in the world). The 747SP was also used by South African Airways on flights from Johannesburg to London, during the Apartheid years, when that airline's aircraft were not allowed to fly over African countries and had to fly around the Bulge of Africa. The extra range allowed aircraft to cover the additional distance.

For all its technical achievements, the SP never sold as well as Boeing hoped, only 45 were ever built and most that are still in service are used by operators in the Middle East.

One special 747SP is the SOFIA astronomical observatory, where the airframe was modified to carry a 2.5-meter-diameter infrared reflecting telescope to high-altitude, the limit to which infrared penetrates the atmosphere. Originally delivered to Pan Am and titled "Clipper Lindbergh", NASA has displayed the name in Pan Am script on the plane. It will fly again in late 2005.

747-300

PIA Boeing 747-300 on final at London Heathrow Airport.
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PIA Boeing 747-300 on final at London Heathrow Airport.

The first incarnation of the 747-300 would have been a trijet version of the 747SP, intended to compete with the DC-10 and L-1011 TriStar. This plan was scrapped due to insufficient demand.

The 747-300 name was revived for a new aircraft, which was introduced in 1980, and was the first 747 model to feature a "stretched upper deck," which increased its capacity over earlier models. Combi (747-300M) and Japanese domestic (747-300SR) models were also built. The upper deck was now accessed via a straight staircase, rather than the spiral steps that featured in the 100 and 200. The maximum range of 747-300 is 7,700 miles (12,400 km).

Airlines currently operating a large number of this type are JAL, Air India, Saudi Arabian Airlines, Pakistan International Airlines (PIA), Qantas, Korean Air, Crossair and Thai Airways

747-400

British Airways 747-400 on the approach to San Francisco International Airport
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British Airways 747-400 on the approach to San Francisco International Airport

The 747-400 is the latest model of the 747, and also the only series still in production. It added 6ft(2m) wing tip extensions and 6ft(2m) winglets, an all-new glass cockpit which dispensed with the need for a flight engineer, tail fuel tanks, revised engines, an all-new interior, and newer in-flight entertainment to the basic design of the -300 series. It first entered service in 1989 with Northwest Airlines. China Airlines is the first airline to take the new "Signature Interior" with the China Airlines/Boeing livery 747-400, the aircraft entering service in 2005.

The -400 is available in the all passenger, combi (747-400M) and freighter (747-400F and 747-400SF) variants. The Japanese domestic variant, the 747-400D, is the highest-capacity passenger aircraft in the world, and will be until the Airbus A380 officially enters service. The -400D lacks the wing tip extensions and winglets included on other variants, allowing for increased number of takeoffs and landings by lowering wing stresses. The -400D may be converted to the long range version when needed.

The 747-400ER is 400's extended range version: it also comes in an all-freight version, the 747-400ERF. Plans to develop a newer model, the 747-400XQLR, which stood for Quiet Long-Range (the X being a designator for an aircraft derivative which is still a design study and has not been officially launched), have evolved into the 747 Advanced.

747 Large Cargo Freighter

Boeing announced in October 2003 that air transport will be the primary method of transportation for 787 parts (as opposed to shipping). Boeing will convert three passenger 747-400 aircraft into an outsize configuration, in order to ferry sub-assemblies to Everett, Washington for final assembly. It has a bulging fuselage like the Super Guppy or Airbus Beluga cargo planes used for transporting wings and fuselage sections.

Delivery times for the wings - built in Japan - will be reduced from around 30 days to one day with the 747 LCF. (See: Boeing news releases [2], [3]).

747X

The 747X was a proposed aircraft design that was similar to the proposed 747-500 among other 747 Stretches. The proposal was dropped when Boeing decided to develop and commercialise the 747Adv (747 Advanced).

747 Advanced

Boeing is now working with airlines to create a new 747 design called the 747 Advanced which will use same engine and cockpit technology as the 787. The new design will be quieter, more economical and more environmentally friendly. It will be capable of carrying up to 450 passengers in a 3-class configuration and fly over 8,000 nautical miles (14,816 km) at .86 Mach. It is rumoured that British Airways, Japan Airlines and Cathay Pacific have shown interest in this model. None of them have purchased the Airbus A380 as of yet. On 27th July 2005, Cargolux announced[4] its desire to buy a minimum of 10 Boeing B747 Advanced Freighters (ADV F) for delivery in 2009.

Government and military

The current U.S. presidential aircraft, VC-25A, is among the most famous 747 models. It is popularly known as Air Force One, although that name technically refers to any United States Air Force aircraft carrying the President. VC-25A is based on the civilian Boeing 747-200. Other special 747s include the E-4B National Emergency Airborne Command Post (referred to colloquially as "Kneecap"), modified 747s to transport the Space Shuttle (Shuttle Carrier Aircraft), and aerial refueling tankers. A recent addition to the military's 747 arsenal is the experimental Airborne Laser, a component of the National Missile Defense plan.

A number of other governments also use the 747 as a VIP transport, including Bahrain, Iran, Japan, Oman, Qatar, Saudi Arabia, Taiwan, and the United Arab Emirates.

Powerplants

(For the last versions of each series offered)

Technical data

Boeing 747
Measurement B747-100 (earliest version) B747-400ER (most modern version)
Length 70.7 m 70.7 m
Span 59.6 m 64.4 m
Height 19.3 m 19.4 m
Wing area 511 m² 541 m²
Weight empty 162.4 t 180.8 t
Maximum take-off weight 340.2 t 412.8 t
Maximum speed 967 km/h 939 km/h
Range fully loaded   9,040 km 14,200 km
Cargo capacity   170.6 CBM (5 pallets + 14 LD1s) 158.6 CBM (4 pallets + 14 LD1s)
Engines (example) 4 × Pratt & Whitney JT9D each with 209 kN thrust 4 × General Electric CF6-80 each with 274 kN thrust
Cockpit Crew Three Two

Facts & trivia

  • A 747-400 has six million parts (half of which are fasteners) made in 33 different countries.
  • Just one engine on a 747 produces more thrust than all four engines on an early model Boeing 707 combined.
  • When pressurized, a 747 fuselage holds over a ton of air.
  • The 747-400 is about 25 percent more fuel efficient than the 747-100, and twice as quiet.
  • Early model 747s have more than 700lbs (300 kg) of depleted uranium molded into the engine nacelles. Its purpose is as ballast to prevent the wing from fluttering.
  • One of the original 747 design proposals was a full double decker, similar to the Airbus A380. Boeing dropped the idea at the eleventh hour, arguing that a wide single decker would be both more economical to operate and safer.
  • During the flight certification period, Boeing built an unusual training device known as "Waddell's Wagon" (named after the 747 test pilot, Jack Waddell) which consisted of a mock-up cockpit mounted on the roof of a truck. It was intended to train pilots on how to taxi the aircraft from the high upper deck position.
  • At the time of its launch, the term "jumbo jet" had already been coined by the media to describe a general class of new wide-bodied airliners then being developed, including the Lockheed L-1011 TriStar and Douglas DC-10. Boeing was quite keen to discourage the media and the public using the term "jumbo jet" for the 747, but their efforts were in vain, and now the term is synonymous with the 747.
  • The 747SP was originally intended to be known as the 747SB (the SB logically standing for "Short Body", before it was nicknamed "Sutter's Balloon" by Boeing employees, being named after 747 chief engineer Joe Sutter). Eventually the name "Special Performance" was used instead.
  • Due to its immense length, there is a very small flexure of the fuselage in flight. This effect was not anticipated in the design of the autopilot on early models, and so there is a very slow oscillation in yaw when flying on autopilot. This was first discovered on an overseas flight to the Paris Airshow, when some of the people in the rear got air sick. Upon return, the plane went through a shake test for two weeks to sort out the problem and adjust the yaw damper system. This solved the problem and the effect is now too small to be noticeable by passengers.
  • To enable easy transportation of spare engines between sites by airlines, the 747 includes the ability to attach a non functioning fifth-pod engine under the port wing of the aircraft, between the nearest functioning engine and the fuselage. Photographs of planes flying in this configuration are highly prized by aircraft enthusiasts. [5] [6]
  • There is another airplane which has a hump on the upper fuselage, the Carvair, which was built from 1961 to 1969. Its most notable appearance is in the 1964 James Bond movie Goldfinger.
  • In the 1970's 747 pilots nicknamed the Jumbo Jet, "The Queen of the Skies" because of it's huge size and capacity.

Preserved aircraft

As increasing numbers of 'classic' 747-100 and 747-200 series are retired, some are finding their way into aircraft museums. They include:

Disasters

Specific accidents

The 747 has been involved in a number of air disasters. However, very few have been due to design flaws in the aircraft itself: as with most air accidents, most have been because of pilot error, improper maintenance, or in a few cases, terrorist or military action.

Accident summary

See Aviation Safety Network for authoritative figures.

  • Hull-loss Accidents: 33 with a total of 2850 fatalities
  • Other hull-loss occurrences: 6 with a total of 857 fatalities
  • Hijackings: 30 with a total of 22 fatalities

Airlines

Most international airlines use the 747 on their busiest routes. However, as point-to-point international service between midsize cities has become more common, some major airlines have replaced their 747s with smaller and more efficient twinjet aircraft. American Airlines, and Continental Airlines are among the larger carriers to discontinue the 747. Other airlines that have removed the type from their fleet include Air Canada, Aer Lingus, SAS, TAP, and Olympic Airways.

The largest fleet of 747s belongs to Japan Airlines, at approximately 73 (series -200s, -300s and 44 -400s). British Airways has the largest fleet of 747-400s at 57.

Future development

The 747 is the only Boeing jetliner never to be stretched beyond its original design length. This has been mainly due to the uncertain economics of the commercial airline business, and the lack of suitable engines. Many different stretching schemes for the 747 have been proposed, but none have come to fruition. The 747-X program was launched in 1996, and was intended to be Boeing's response to Airbus' A3XX proposal. The 747-X would have consisted of the 747-500X and 747-600X which would have provided seating for up to 800 passengers. General Electric and P&W formed the Engine Alliance and designed the GP7200 turbofan to power the stretched 747. Airlines, however, would have preferred Boeing to develop an all-new design instead of an updated 747, and the plan was dropped after a few months.

When the Airbus A380 was formally launched in 2000, Boeing dusted off its 747-X studies in a bid to thwart sales of the Airbus competitor. But once again airlines were not interested, and Boeing cancelled the program in 2001 after no orders were forthcoming, devoting its energies to the ill-fated Sonic Cruiser. Some of the ideas developed for the 747-X were, however, used in the production of the 747-400ER.

The long-term future of the 747 is now in doubt—its dominance on long-haul routes has been eroded in recent years by the new generation of ETOPS-compatible twinjets such as the Airbus A330 and Boeing's own 767 and 777. Despite Boeing's claims that the A380 can never be profitable, Airbus has already sold a considerable number of the giant aircraft. Previously loyal 747 customers such as Qantas, Virgin Atlantic and Singapore Airlines have ordered the A380, and sales of the passenger 747 have dwindled to almost nothing. The most recent order for a passenger 747 was in November 2002 and only 16 have been delivered since then. Freighter versions of the 747 have kept the production line going although orders for these have also declined in recent years, many carriers preferring to convert passenger aircraft such as MD-11s to freighters.

Nonetheless, in early 2004, Boeing rolled out tentative plans for what it calls the 747 Advanced. As the first A380 prototypes edged ever closer to their first flight, this was evidence that the company was prepared to challenge Airbus. Essentially another "recycle" of 747-X plan, the stretched 747 Advanced will use advanced technology from the 787 to update the aircraft. Eventually, the 747 (in all forms) will be replaced by a clean-sheet aircraft dubbed "Y3," though its entry into service will be affected by board approval (or lack thereof) for the 747 Advanced.

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