Science Fair Project Encyclopedia
The Boeing 747, which is also known as the jumbo jet, is the second largest passenger airliner after the Airbus A380. Until the first commercial flight of the A380 in 2006, however, it remains the largest passenger aircraft in commercial service.
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 recognisable 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 sufficient to fly from New York to Hong Kong (roughly a third of the globe) non-stop. In 1989 a Qantas 747-400 flew non-stop from London to Sydney, a distance of 11,185 miles (18,000 km), in 20 h 9 min: this was a delivery flight with no passengers or freight aboard. By May 2004, a total of 1381 aircraft have been built or ordered in various 747 configurations, making it a profitable product for Boeing.
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 revolutionised 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 which 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 design was a full length double decker, but due to issues with evacuation routes this idea was 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. Boeing took the shrewd move and designed the 747 so that it could easily be adapted to carry freight, knowing that when sales of the passenger version dried up, it 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, creating the 747's distinctive "bulge." However, the supersonic transports such as Boeing's still-born SST and the Concorde never lived up to their promise, being too expensive to operate profitably at a time when fuel prices were soaring. The upper deck was initially used as a luxurious first-class lounge/bar area, but is now most often used for extra seating capacity. After being expected to wither on the vine with only 400 sales, 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 favor of the cargo derivative has only happened in the early 2000s.
The development of the 747 was a huge undertaking. Boeing did not have a factory large enough to assemble the giant aircraft, so the company built an all-new assembly building near Everett, Washington. This factory is the largest building ever built. Pratt and Whitney developed a massive high-bypass turbofan engine, the JT9D, that was, in the beginning, exclusively for 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 which allow 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 and instead invested in tri-jets. Furthermore, there was worry about whether the 747 would 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 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 was only broken 35 years later with the advent of the Airbus A380.
The first edition of the jet, the 747-100, rolled out of the new Everett facility on 2 September 1968. The 747-100 entered service on 1 January 1970 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. Another 100 variant, the 747-100SR, has a capacity of up to 550 passengers and is used on domestic flights in Japan. The basic 100 has a range of about 4,500 miles (7200 km) with full load.
747-100 aircraft can be distinguished from other aircraft by the upper deck, which normally has only three windows. There are exceptions. Also, some airlines purchased "SUD," or "stretched upper deck" modifications, which make the upper deck almost identical to a 747-300.
Introduced in 1971, and further improved over successive years, the 747-200 has higher thrust and weight-lifting capability than the 747-100, flying farther. It can usually be distinguished by its eight-window upper deck (but, again, some airlines have given their 200 aircraft SUD, and a few early 200s had just 3 windows). 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.
The 747SP, or "Special Performance," was first delivered in 1976. The SP was largely a stop-gap model to compete with the Douglas DC-10 and Lockheed L-1011 TriStar. 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 TriStar 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 reoptimised it for speed and range at the expense of capacity. The SP could 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.
The 747SP was the longest-flying airliner available until the Airbus A340, and found its way into the fleets of American Airlines, Pan Am, and Qantas, airlines that needed its range for trans-South Pacific routes. (American later used its 747SP's for services to Tokyo.) The 747SP was also used by South African Airways on flights from Johannesburg to London, during the Apartheid years, when 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.
The SOFIA astronomical observatory is a 747SP modified to carry a 2.5-meter-diameter infrared reflecting telescope. Originally delivered to Pan Am and titled "Clipper Lindbergh". NASA has displayed the name in Pan Am script on models of the plane. It will fly again in late 2005.
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 747-400 is the latest model of the 747, and also the only series still in production. It added 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.
The -400 is available in combi (747-400M) and freighter (747-400F) variants. The Japanese domestic variant, the 747-400D, is the highest-capacity passenger aircraft in the world, capable of carrying 568 passengers. The -400D lacks the winglets included on other variants.
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 7E7/787 parts (as opposed to shipping). Boeing will convert four passenger 747-400 aircraft into an outsize configuration, in order to ferry subassemblies 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 will be reduced from around 30 days to one day with the 747 transporter. This is extremely important for the 787 as the wings are being produced by Japanese subcontractors.
Boeing is now working with airlines to create a new 747 called the Boeing 747 Advanced which will use same engine and cockpit technology as the 787 . The new 747 will be quieter, more economical and environmentally friendly. It will be capable of carrying up to 500 passengers in a 3-class configuration and fly over 8,000 nautical miles (14,816 km) at .86 Mach.
Government and military models
The current U.S. Presidential aircraft, VC-25A, is among the most famous 747 models. It is popularly known as Air Force One, even though that name 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 airborne emergency command and control post, 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.
(For the last versions of each series offered)
|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 mē||541 mē|
|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||6025 CBM (5 pallets + 14 LD1s)||5599 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|
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 pressurised, 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 seven hundred pounds (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 a bizarre 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). The eventual 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.
As increasing numbers of 'classic' 747-100 and 747-200 series are retired, some are finding their way into aircraft museums. They include:
- Boeing 747-100 N7470, the first 747 prototype Museum of Flight, Seattle
- KLM 747-200(SUD) PH-BUK at Lelystad
- Qantas 747-200 VH-EBQ at Longreach Airport, Queensland
- South African Airways 747-200 ZS-SAN at Rand Airport , Johannesburg
- Lufthansa 747-200 D-ABYM at Speyer, Germany
- Air France 747-100 F-BPVJ at Le Bourget, Paris
The 747 has been involved in a number of air disasters. However, very few have been due to design flaws in the aircraft itself: most have been because of pilot error, improper maintenance, or in a few cases, terrorist or military action.
- Lufthansa flight 540, Nairobi, 1974
- Tenerife Airport Disaster, 1977
- Air-India flight 855, Arabian Sea, 1978
- Korean Air flight 007, Sea of Okhotsk, 1983
- Avianca flight 011, Madrid, 1983
- Air-India flight 182, Atlantic Ocean, 1985
- Japan Airlines flight 123, Tokyo, 1985
- South African Airways flight 295, Indian Ocean, 1987
- Pan Am flight 103, Lockerbie, 1988
- China Airlines flight 358, Taiwan, 1991
- El Al cargo flight 1862, Amsterdam 1992
- Philippine Airlines Flight 434, Okinawa, 1994
- TWA Flight 800, Long Island, 1996
- Saudia flight 763, Delhi, 1996
- Korean Air flight 801, Guam, 1997
- Singapore Airlines flight 006, Taipei, 2000
- China Airlines flight 611, Penghu Islands, 2002
- Hull-loss Accidents: 30 with a total of 2843 fatalities
- Other occurrences: 6 with a total of 857 fatalities
- Hijackings: 29 with a total of 22 fatalities
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 747's 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 Aer Lingus, SAS, TAP, and Olympic Airways.
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 A300 and Boeing's own 767 and 777. Despite Boeing's claims that the A380 can never be profitable, Airbus have 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 vast majority of 747s made now are freighters. Boeing has promised that it will always be ready to produce larger, more advanced versions of the 747 when the market for such a plane develops, but industry analysts are already predicting the end for the 35-year old giant.
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 to Airbus. Essentially another "recycle" of 747-X plan, the stretched 747A intends to use technology from the 787 to bring the 747 into the new millennium. Time will tell if Boeing manages to get this "paper airplane" into production.
- Airliners.net - Boeing 747-100 & 200
- Airliners.net - Boeing 747-300
- Airliners.net - Boeing 747-400
- Airliners.net 747 images
- Calipso: Boeing 747 Information & History
- Aircraft-Info.net - Boeing 747-400
- Planemad.net - Boeing 747 Production Lists
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