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Boeing 777

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In 1985, studies were centered around a 21ft (6.4m)-stretch of the 767-300, dubbed the -400 (the 777 designation was first publicized in 1978, linked to proposed tri-jet versions of the 767), with the same fuel capacity, engines, and gross weight of the 767-300. A longer range development was possible, but would require "some wing work," said Boeing.


Market assessment for the derivative began late in 1986 and proceeded at a rather leisurely pace. The launch of the MD-11, followed by the A330/A340, stimulated Boeing's efforts and by the third quarter of 1988, the manufacturer was discussing a wide range of derivatives of the 767 with airlines, grouped in three categories under the 767-X nomenclature. The least expensive proposal was a slightly stretched 767-300 which retained the existing wing, but resulted in only a modest capacity increase. A 'maximum change' 767 would have wing tip extensions and winglets, plus the additional of a wing root insert.


The most expensive suggestion featured a completely new wing (called 767RW, or Re-Wing) that would allow a significant fuselage stretch - as much as 539in (44ft llin/13.69m) - although the span would be such that it could pose airport gate compatibility problems.


The dozen different studies included several designs with second decks, including one 9ft (2.74m) stretch with a partial upper deck aft of the wing.


All of the 767-X designs would have required powerplants with increased thrust over existing 767 engines, although at the time Boeing stated that they would not need a re-fanned engine, proposed by all three engine manufacturers - General Electric, Pratt & Whitney, and Rolls-Royce - to meet the 67,500-71,000 lb st (300.2-315.8kN) requirements of Airbus for the A330.


Boeing's market research indicated that the 767-X would have to satisfy three different markets. The A-Market aircraft, intended for US transcontinental, Europe-Asia, and intra-Asia routes, would be a 300-seater with a range of 4,000nm (7,400km). Next in significance was the B-Market, aimed at the evolving North Atlantic extended-range twin-jet segment (then known by the acronym EROPS, for Extended Range OperationS). The 250-seat air-craft would have a range of 5,500nm (10,200km) and be capable of flying between secondary US and European destinations, such as Dallas-Frankfurt. Finally, there was a future C-Market proposal, for twin-jet operations between the US West Coast and Asia, and between Europe and the Orient. This 230-seat aircraft (about the same size as a 767-300) would have a range of 7,000nm (13,000km).


Boeing - which traditionally had only consulted with one or two prospective launch customers - invited representatives of eight airlines (All Nippon Airways, American Airlines, British Airways, Cathay Pacific Airways, Delta Air Lines, Japan Airlines, QANTAS, and United) to form a steering committee. The 'Gang of Eight' met regularly in Seattle, and helped to define the 767-X


Several driving forces for the 767-X emerged by spring 1989, including serious interest from All Nippon and United. By then, enthusiasm for the double deck proposals had waned in favor of a new nine-abreast design, retaining only the nose and tail of the 767. Re-fanned engines would be a necessity, and the designation 787 was linked briefly to the aircraft which would be available from mid-1995.


On December 8,1989, Boeing's board of directors authorized the company's salesmen to make firm offers of a 767-X design which, when formally launched, would become the 777. The basic con-figuration was a wide-body twin with a twin-aisle cabin "wider than the 767, A330, or MD-1l," to seat around 350 passengers in a two-class layout with a range of 4,200nm (7,800km). Its wing span was considerably greater than that of the 767-300, and only slightly less than that of the 747-400. One option under study was the incorporation of folding wing tips. While the chosen design involved the highest development costs, it also allowed for the most growth in the future.
This aircraft was the first fly-by-wire passenger aircraft for Boeing and many other firsts were incorporated in this aircraft, including an advanced glass cockpit, the large-scale use of composite materials, extremely powerful engines, and Boeing also used computers to design and electronically preassemble the entire airplane. The cockpit has five large 200-mm liquid-crystal, multi-function display (MFD) screens, with an additional screen on the central console panel. This MFD, along with the centre display on the panel, is used for the aircraft’s engine indication and crew alerting system (EICAS), while each pilot has two main screens in front of them which are used as primary flight displays (PFD) and the navigation displays (ND).


The B777 is a true fly-by-wire aircraft. The primary flight-control system (PFCS) has two types of computers in its system: the actuator control electronics (ACE) which is primarily an analogue device, and the primary flight computer (PFC) which is digital. There are four ACEs and three PFCs and, furthermore, the PFCs have three chan-nels for operation. The four ACEs receive the data from multiple transducers on the pilot controls and those on the primary surface actuators. This is then converted to digital and sent over the “triplex hi-directional buses” to the PFCs. These are then returned over the same buses (hi-directional remember) for the ACEs to convert these signals back into analogue commands for each actuator. The aircraft systems then operate the flight con-trols.


Three engine types have been offered to power the B777: the Rolls-Royce Trent 800, the Pratt & Whitney PW4000 and the Gen-eral Electric GE 90. The fan diameters are incredibly large with the largest, the GE 90, measuring 3.12 metres. These engines have been rated from 74,000 lbs for the original P&W PW4074, to the largest, 98,000 lbs, of the P&W PW4098.


Although a 239in (19ft llin/6.07m) cross section was studied, eventually the fuselage diameter was set at 244in (20ft 4in/6.2m), compared to 237in (19ft 9in/6.02m) for the MD-11 and 222in 08ft 6in/5.64m) for the A330/A340. Consequently, Boeing claims that the 777 offers more interior options and greater flexibility than the competition, from a six-abreast first-class layout with 21in (53cm)-wide seats to a ten-abreast economy section with 'industry-standard comfort levels' (which translates to 17in (43cm)-wide seats with a 32in (81cm)-pitch).


Originally, the new aircraft was to retain considerable systems commonality with the 767, but in the event only some of the cockpit structure was retained. Because of customer preference the layout of the 777's two-person flight deck is similar to that of the 747-400. However, instead of CRT (Cathode Ray Tube) screens, six flat-panel Liquid Crystal Displays (LCDs) show flight, engine, and navigation information. In addition to saving space, LCDs weigh less, require less power, and generate less heat than CRT displays. Even the three standby gauges are LCDs; a compass is the only 'dial' survivor from previous generation cockpits.


The aircraft’s total fuel capacity is accommodated entirely within the wing and structural centre section.


Although Boeing had indicated it would prefer to have at least 100 orders for its new design, the 777-200 (there was no -100) was launched on October 29, 1990, following on the heels of an initial order for 34 (plus 34 options) from United. All Nippon took the plunge (for 15 plus 10 options) that December, the same month that a revised memorandum of understanding (MOU) was signed by Boeing, Fuji, Kawasaki, and Mitsubishi for the Japanese to assume responsibility for 20% of the airframe along with a corre-sponding share in the market risk and the potential rewards. The first -200 B -Market order came from French charter airline Euralair the following June.


The 777 is the subject of Boeing's most extensive flight testing program ever, with no less than nine aircraft and three different engines involved. At its conclusion in June 1996, Boeing expected the test fleet to have logged 7,000hr and 4,900 cycles.


The first 777-200 (registered N7771 and named Working Together) PW4077-powered made its maiden flight on June 12, 1994, in the hands of John Cashman, 777 chief pilot, and Ken Higgins, director of flight test. It has conducted aerodynamic, stability, and control testing to basic certification and will continue follow-on testing until June 1996, then be refurbished for sale.


Four PW-powered -222s for United had joined in the flight testing by October 1994 and have been followed by two -236s with CE90 engines for British Airways. The first two -267s for Cathay Pacific, completed in April and June 1995, respectively, were assigned to complete certification of the Rolls-Royce Trent.


United accepted its first 777, appropriately registered N777UA, also the first of the type to be delivered, on May 15 1995, and this aircraft was the centerpiece of a formal delivery celebration two days later. United placed the three-class 292-seat 777 into service on June 7 with a London (Heathrow)-Washington (Dulles) flight.


Two versions of the 777 were available: the basic -200 and the increased gross weight -2001GW, which has since been renamed the -200ER. The first Boeing 777-200 flew on 12 June 1994, and was awarded FAA and JAA certification on 19 April 1995. This longer range B777-200ER can fly more than 7,200 nm. The PW4074 powered aircraft was awarded the 180-minute ETOPS (extended twin-engine operations) in May of 1995. Ten metres longer than the 777-200, the 777-300 has dimensions that all but match the 747; seating around 550 passengers in a single class, or 368-386 passengers in three classes, with a range of over 8,500 nm. Both the -200 and -300 series have a wing span of 60.9 m, nearly identical to that of the Boeing 747-100 and -200. The -300 was rolled out on 8 September 1997, first flew on 16 October 1997 and has since gained 180-mm ETOPS approval and JAA/FAA certification. The 777-300ER first flew on 24 February 2003. As part of the test programme, the 737-300ER set a MTOW record of 774,600 lb.


Compared to the 747-400, as ER cruises at similar speeds (0.84 Mach as compared with the 747's 0.85 Mach) and can carry only slightly less passengers. The 777-300ER has a range of more than 7,400 nm. The aircraft has an advanced fly-by-wire flightdeck featuring lightweight liquid crystal displays, and Jeppesen's "Electronic Flight Bag" the latest advance towards the paperless flightdeck.


The B777-300ER is powered by two General Electric GE90-115B1 engines, which are capable of 115,000 lbs of thrust each. These engines include composite fan blades instead of the typical titanium blades, and the blade's swept-design is reported to add 2,000 lbs to the engine thrust.


Two prototypes undertook the 1500 hours of flight testing required for certification.


The new 777-346ER has a MTOW of 759,600 lbs (344,555 kg), a range of 7,430 nautical miles (13,760 km), and two GE90-115B engines of 115,000 lbs thrust each - the world's most powerful commercial jet engine. Differences over the standard 777 include; the wings extended by 6.5 feet, with raked tips; strengthened wings and empennage; strengthened nose undercarriage, with a new upgraded main landing gear installed; supplementary electronic tail-skid added and the nacelle struts modified to accommodate the higher thrust engines.

777-200
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).

Engine: 74,500 lb st (331.3kN) Pratt & Whitney PW4074.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 506,000 lb (229,520kg), 515,000 lb (233,600kg)(option).

Engine: 77,200 lb st (343.4kN) Pratt & Whitney PW4077.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 506,000 lb (229,520kg), 515,000 lb (233,600kg)(option).

Engine: 84,600 lb st (376.3kN) Pratt & Whitney PW4084.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 580,000 lb (263,090kg), 590,000 lb (267,620kg)(option).

Engine: 90,000 lb-st (400.3kN) Pratt & Whitney PW4090.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 632,500 lb (286,900kg).

Engine: 74,500 lb-st (331.4kN) General Electric GE90-7584.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 632,500 lb (286,900kg).

Engine: 76,400 lb st (339.8kN) General Electric GE90-76B4.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 632,500 lb (286,900kg).

Engine: 84,700 lb st (376.7kN) General Electric GE90-85B4.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 632,500 lb (286,900kg).

Engine: 90,000 lb st (4003kN) General Electric GE90-90B4.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 632,500 lb (286,900kg).

Engine: 74,600 lb st (331.8kN) Rolls-Royce Trent 875.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 632,500 lb (286,900kg).

Engine: 76,900 lb st (342.0kN) Rolls-Royce Trent 877.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 632,500 lb (286,900kg).

Engine: 84,300 lb st (375.0kN) Rolls-Royce Trent 884.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 580,000 lb (263,090kg), 590,000 lb (267,620kg)(option).

Engine: 90,000 lb st (400,3kN) Rolls-Royce Trent 890.
Wing span: 199 ft 11 in (60.93m).
Length: 2099 ft 1 in (63.73m).
Height: 60ft 9in (18.51 m).
Wing area: 4,605sq.ft (427.8sq.m).
Fuselage diameter: 20ft 4in (6.20m).
Cabin diameter: 19ft 3in (5.87m).
MGTOW: 632,500 lb (286,900kg).

777-200B
Engines: 2 x Pratt & Whitney PW4090, 90,000 lb thrust.
Wing span: 60.9 m.
Wing area: 430 sq.m.
Fuel capacity: 171,155 lt.
MTOW: 290.29 tonne.
Max cruise: M0.87.

777-200ER
Engines: 2 x General Electric GE90-94B.

777-200ER
2 x Rolls-Royce Trent 892, 92,000-lb-thrust.
MTOW: 286.89 tonnes.
MLW: 208.65 tonnes.
Zero fuel wt: 195.04 tonnes.
Crew: 15.
Fuel cap: 275 tonne.
Certified ceiling: 43,100 ft.

777-269IGW

777-300
Engines: 2 x General Electric GE90.
Length: 73.9m.
Max cruise: M0.89.

777-300ER
Engines: 2 x General Electric GE90-115B1, 115,000 lb thrust.

777-346ER
Engines: General Electric GE90-115B, 115,000 lbs.
MTOW: 759,600 lbs (344,555 kg).
Range: 7,430 nm (13,760 km).
Pax cap: 365.

 

 


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