Science Fair Project Encyclopedia
The Boeing 777 is a family of long range widebody twin engine airliners built by Boeing Commercial Airplanes. It carries between 305 and 550 passengers and has a range from 5,600 to 8,870 nautical miles (10,400 to 16,400 km). The first flight of the 777 was in 1994.
Distinguishing features of the 777 include the set of six wheels on each main landing gear, its perfectly circular fuselage cross section, and the blade- like rear tailcone.
In the 1970s Boeing unveiled new models to replace and expand its line up. They were the twin engined 757, to replace the venerable 727; the twin engined 767 to challenge the Airbus A300 and the 777 trijet to compete with the DC-10 and the Lockheed TriStar.
It was a trijet airplane based on a re-winged 767 design, with two main variants: a transcontinental airplane transporting 175 on trips up to 5,000 km (2,700 nautical miles) and an intercontinental version capable of flying over 8,000 km (4,320 nautical miles) with the same passenger load.
The twinjets were launched and the 777 trijet was cancelled. Boeing's choice to not proceed with the 777 was influenced by the design complexities of trijet aircraft, the absence of an engine with thrust in the range of 40,000 lbf (178 kN), and the success of the 757 and 767, particularly with the benefit of ETOPS regulations of the 1980s.
Boeing had a big gap in its product line between the 767-300ER and the 747-400 in terms of size and range, and realized the potential of such an airplane. The DC-10 and Lockheed Tristar, being of 1960s design, were also ripe for replacement. In the meantime, Airbus developed the A330 and A340 to fulfill that requirement.
The initial proposal from Boeing was simply to enlarge the 767, resulting in the 767-X concept. It was similar to a 767 but with a longer fuselage and larger wings seating about 340 passengers and with a maximum range of 7,300 nautical miles (13,500 km).
The airlines were unimpressed with the 767-X. They wanted short to intercontinental range capability, cabin cross section similar to the 747, a fully flexible cabin configuration and an operating cost lower than any 767 stretch. The result was a new design, the 777 twinjet.
The design phase of the 777 differed from previous Boeing jetliners. For the first time, the airlines and their passengers had a role in the development of the plane. The "Working Together" philosophy, as Boeing called it, meant that the 777 was their most customer oriented aircraft yet.
The 777 was also the first commercial aircraft to be designed entirely by computer. No paper drawings were ever produced; everything was created on a 3D CAD software system known as CATIA. This allowed a virtual 777 to be assembled in cyberspace, allowing engineers to examine for interferences, and to test if the many thousands of parts would fit together properly before costly physical prototypes were manufactured.
To satisfy airline requirements, technology new to Boeing was employed, although much of this technology was already in service on Airbus aircraft. These new features included:
- Honeywell LCD glass cockpit flight displays
- Fully digital fly-by-wire flight controls
- Fully software configurable avionics
- Large scale use of composites (10% by weight)
- Fiber optic avionics network
- Very large turbofan engines
Fortunately for Boeing, work done on the previously cancelled Boeing 7J7 validated the chosen technologies. The 777 first flew on June 14, 1994 and underwent a flight test programme more extensive than any other Boeing models. Boeing pioneered the Early ETOPS process giving the 777 180 min ETOPS rating entry into service. The FAA awarded full 180 minutes ETOPS clearance for PW4074 777-200s on May 30, 1995.
A notable design feature is Boeing's decision to retain conventional control yokes rather than fit sidestick controllers as used in many fly-by-wire fighter aircraft and in some Airbus models. Boeing viewed 'stick and rudder ' controls as being more intuitive for pilots.
Boeing uses two characteristics to define their 777 models. The first is the airframe size, which affects the amount of passengers and cargo that can be carried. The 777-200 and derivatives are the base size, while the aircraft was stretched into the 777-300.
The second characteristic is range. Boeing defines three segments:
- A market - 3,900 to 5,200 nautical miles (7,200 to 9,700 km)
- B market - 5,800 to 7,700 nautical miles (10,800 to 14,250 km)
- C market - 8,000 nautical miles (14,800 km) and greater
When referring to variants of the 777, Boeing and the airlines often collapse the model (777) and the capacity designator (200 or 300) into a smaller form, either 772 or 773. Subsequent to that, they may or may not append the range identifier. So the base 777-200 may be referred to as a "772" or "772A," while a 777-300ER would be referred to as a "773ER" or "773B." Any of these notations may be found in aircraft manuals or airline timetables.
The 777-100 (771B) would have been a lower capacity, B market version of the 777. As the aircraft would have been heavy and have high per passenger costs, it was not selected for production. History has not been kind to "shrinks" of aircraft—the Airbus A318, Boeing 747SP, Boeing 737-600, and McDonnell Douglas MD-87 are excellent examples. The 777-100 was offered to Delta Air Lines and Continental Airlines as an option to replace their aging L-1011 and DC-10 fleets. Both airlines rejected the offer, which led Boeing to make the 767-400ER, which was designed to meet both of their specifications. The 787-9 will be targeted at this same market segment.
The 777-200 (772A) was the initial B-market model. The first customer delivery was to United Airlines in May, 1995. It is available with a maximum take-off weight (MTOW) from 229 to 247 tonnes and range capability between 3780 and 5150 nautical mile (7000 to 9500 km).
The direct Airbus equivalent is the A330-300.
Originally known as the 777-200IGW (for "increased gross weight"), the longer-range B market 777-200ER (772B) features additional fuel capacity, with increased MTOW range from 263 to 286 tonnes and range capability between 6000 and 7700 nautical miles (11,000 to 14,300 km). The first 777-200ER was delivered to British Airways in February 1997.
The 777-200ER can be powered by any two of a number of engines: the 84,000 lbf (374 kN) PW4084 or Trent 884, the 85,000 lbf (378 kN) GE90-85B, the 90,000 lbf (400 kN) PW4090, GE90-90B1, or Trent 890, or the 92,000 lbf (409 kN) GE90-92B.
On April 2, 1997 a Boeing 777-200ER, tail registration 9M-MRA (dubbed the "Super Ranger") of Malaysia Airlines, broke the Great Circle Distance Without Landing record for an airliner by flying east (the long way) from Boeing Field, Seattle, to Kuala Lumpur, Malaysia, covering the distance of 20,044 km in 21 hours, 23 minutes.
The direct Airbus equivalent is the A340-300.
Boeing claims the C market 777-200LR (772C) will be the world's longest ranging commercial airliner, capable of flying 9420 nautical miles (17,446 km) in 18 hours. It will achieve this with huge 110,000 lbf (489 kN) thrust GE90-110B1L turbofans, a significantly increased MTOW and optional auxiliary fuel tanks in the rear cargo hold. Other new features include raked wingtips, a new main landing gear and additional structural strengthening. The Roll-out was at February, 15th, 2005. The first flight was at March, 8th, 2005, with EIS in January 2006. After the introduction of the 777-200LR, the only mass-produced aircraft with greater unrefuelled range will be the KC-10 Extender.
The direct Airbus equivalent is the A340-500.
The stretched A market 777-300 (773A) is designed as a replacement for 747-100s and -200s. Compared to the older 747s, the stretched 777 has comparable passenger capacity and range, but burns one third less fuel and demands 40% lower maintenance costs.
It features a 33 ft 3 in (10.1 m) fuselage stretch over the baseline 777-200, allowing seating for up to 550 passengers in a single class high density configuration and is also 13 tonnes heavier. The 777-300 has tailskid and ground manoeuvring cameras mounted on the horizontal tail and underneath the forward fuselage to aid pilots during taxi due to the aircraft's enormous length.
The typical operating range with 386 three class passengers is 5720 nautical miles (10,600 km). It is typically powered by two of the following engines: 90,000 lbf (400 kN) PW4090 turbofans, 92,000 lbf (409 kN) Trent 892 or General Electric GE90-92Bs, or 98,000 lbf (436 kN) PW-4098s.
This aircraft has no direct Airbus equivalent, but the A340-600 is offered in competition.
The B market 777-300ER (773B) series is a long range version of 777-300, and is designed as a replacement for the 747-400. This is a result of Boeing's strategy to target the 747 series as cargo freighters rather than passenger aircraft.
The 777-300ER contains many modifications, including the GE90-115B engines, which are currently the world's most powerful jet engine with 115,300 lbf (513 kN) thrust. Other features include raked wingtips, a new main landing gear, extra fuel tanks, as well as strengthened fuselage, wings, empennage, nose gear, engine struts and nacelles. The range on initial versions is 7,250 nautical miles (13,400 km) with a 365 passenger three-class configuration, though after July of 2004, the 300ER will have a range of 7,880 nautical miles (14,594 km). The 777-300ER programme was launched by Air France, though for political reasons, Japan Airlines was advertised as the launch customer . The first flight of the 777-300ER was February 24, 2003.
The direct Airbus equivalent is the A340-600.
The 777 Freighter (777F) is an all-cargo variant of the 777. Boeing has had some need for a large freighter to replace older 747F and MD-11F freighters. The increased payload capability of the 777-200LR has allowed the company to begin marketing a cargo derivation. The model was officially offered starting on November 15, 2004.
The 777F promises excellent operating economics compared to existing freighters. The aircraft has a large interior volume and a high thrust-to-weight ratio. The large wings allow for a low wing loading. The 777F will have a payload of 101 tons. This compares favorably to that of the much larger 747-400F, which has a payload of 124 tons.
With the extra belly fuel tanks sacrificed in the interest of payload, the 777F will not range as far as the passenger variant it is based upon. However, the 777F will be the longest-ranged freighter in the world with a range of 5,200 miles (8,400 km). Compared to the 747F, the 777F will lack direct loading of cargo via the nose, but this will not be an issue for most customers.
The 777F will be equipped with the 110,000 lbf (489 kN) GE90-110B engines from the 777-200LR. However, the 115,000 lbf (513 kN) GE90-115B engines from the 777-300ER may be offered as an option, to increase MTOW.
Potential customers are Lufthansa Cargo, Federal Express, United Parcel Service, Emirates, and EVA Cargo. EIS is 2008. Air France KLM signed on as the 777F launch customer on March 25, 2005. The order for 7 aircraft is worth US$1.5 billion at list prices, and the first delivery will be in 2008.
Airbus has no comparable aircraft—the A380-800F is the closest equivalent, but is larger and does not range as far. In addition the A380-800F is better suited for bulky parcel freight service, while the 777F is geared towards denser cargo. The most directly comparable aircraft is the McDonnell Douglas MD-11F, which also lacks the 777F's range, as well as uplift capability.
- Cruise speed: 0.84 Mach, 550 mph (885 km/h) at 35,000 ft (10,700 m)
- Wingspan: 199 ft 11 in (60.9 m) for -200/-200ER/-300, 212 ft 7 in (64.8 m) for -200LR/-200F/-300ER
- Length: 209 ft 1 in (63.7 m) (-200), 242 ft 4 in (73.9 m) (-300/-300ER) and longer than 747-400
Some Boeing 777 facts
- The 777-300ER is the third largest commercial passenger airplane after the 747-400 and the new A380 and has been tested with a maximum take-off weight (MTOW) of 351 metric tons.
- The 777's undercarriage is the largest ever used in a commercial jetliner, and its tires are the largest ever fitted to a commercial aircraft.
- The 777-300ER has been tested flying with only one working engine for as long as six hours 29 minutes over the Pacific Ocean as part of its ETOPS trials. (Note: 3 hours successful and reliable operation of one-engine-out is sufficient for ETOPS 180 min certification, based on current rules.)
- The GE90-110B and -115B engines (including nacelle) fitted on the 777-200LR and -300ER have a diameter larger than that of a 737 fuselage. The Guinness Book of World Records recognized the -115B, powering the 777-300ER, as the "World's Most Powerful Commercial Jet Engine" with a tested thrust of 127,900 lbf (569 kN).
- The longest ETOPS-related emergency flight diversion (192 min. under one engine power) was conducted on a United Airlines' Boeing 777-200ER, carrying 255 passengers, on March 17, 2003 over the southern Pacific ocean.
- The 777 has substantial non-US designed or non-US manufactured content, to be exceeded only by the 787. At least the following companies have made contributions: Mitsubishi Heavy Industries (fuselage panels), Kawasaki Heavy Industries (fuselage panels), Fuji Heavy Industries, Ltd. (center wing section), Ilyushin (jointly designed overhead baggage compartment).
- The 777 has the same Section 41 as the 767. This refers to the part of the aircraft from the very tip of the nose, going to just behind the cockpit windows. From a head-on view, the end of the section is very evident. This is where the bulk of the aircraft's avionics are stored.
As of April 2005, there have been no fatal accidents involving Boeing 777s, and none of the incidents which have occurred have resulted in the hull being written off.
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