Boeing 777

Boeing 777

Boeing 777-200 of United Airlines, the launch customer of the 777
Role	Wide-body jet airliner
National origin	United States
Manufacturer	Boeing Commercial Airplanes
First flight	June 12, 1994
Introduction	June 7, 1995 with United Airlines
Status	In production
Primary users	Singapore Airlines Emirates Airline United Airlines Air France
Produced	1993–present
Number built	784 as of May 31, 2009^[1]
Unit cost	777-200ER: US$205.5-231.0 million^[2] 777-200LR: US$237.5-263.5 million^[2] 777-300ER: US$257.0-286.5 million^[2] 777F: US$252.5-260.5 million^[2]

The Boeing 777 is a long-range, wide-body twin-engine airliner manufactured by Boeing Commercial Airplanes. The world's largest twinjet and commonly referred to as the "Triple Seven", the aircraft can carry between 283 and 368 passengers in a three-class configuration and has a range from 5,235 to 9,380 nautical miles (9,695 to 17,372 km). Distinguishing features of the 777 include the largest diameter turbofan engines of any aircraft, six wheels on each main landing gear, its circular fuselage cross-section, and the blade-like end to the tail cone.

Designed to bridge the capacity difference between the 767 and 747, the Boeing 777 is produced in two fuselage lengths. The original 777-200 model first entered service in 1995, and the stretched 777-300, which is 33.3 ft (10.1 m) longer, was introduced in 1998. The longer-range 777-300ER and 777-200LR variants entered service in 2004 and 2006, respectively, while a freighter version, the 777F, first flew in 2008. Both long-range 777 models and the 777F are equipped with General Electric GE90 engines, wingtip extensions of 12.8 ft (3.9 m), and raked wingtips. The 777-200LR is the world's longest-range airliner and holds the record for longest distance flown by an unrefueled commercial airliner.

The Boeing 777 entered commercial airline service with United Airlines in 1995. As of 2008, Singapore Airlines operates the largest 777 fleet of any airline. The most common 777 variant used worldwide is the 777-200ER, an extended range version of the original 777-200, with 410 aircraft delivered as of May 31, 2009. In total, 56 customers have placed orders for 1,107 777s, with 784 delivered as of May 31, 2009.

Through the 2000s, the Boeing 777 has emerged as one of its manufacturer's best-selling models. Because of rising fuel costs, airlines have acquired the 777 as a comparatively fuel-efficient alternative to other wide-body jets and have increasingly used the aircraft on long-haul, transoceanic routes. Direct market competitors to the 777 include the Airbus A330-300 and the A340, with the upcoming A350 XWB and Boeing 787 programs currently in development.

Development

Background

In the early 1970s, the Boeing 747, Douglas DC-10, and the Lockheed L-1011 TriStar became the first generation of wide-body passenger airliners to enter service. In 1978, Boeing unveiled three new models: the twin-engine 757 to replace the venerable 727, the twin-engine 767 to challenge the Airbus A300, and a trijet 777 concept to compete with the DC-10 and L-1011. The 757 and 767 twinjets were a success, due in part to the 1980s Extended-range Twin-engine Operational Performance Standards (ETOPS) regulations governing transoceanic twinjet operations. Those regulations allowed twinjet aircraft to fly long-distance overseas routes at up to three hours' distance from emergency diversionary airports. The trijet 777 was later dropped, following marketing studies that favored the 757 and 767 variants. Boeing was left with a size and range gap in its product line between the 767-300ER and the 747-400.

By the 1980s, DC-10 and L-1011 models were approaching retirement, prompting manufacturers to develop replacement designs. McDonnell Douglas was working on the MD-11, a stretched and upgraded version of the DC-10, while Airbus was developing the A330 and A340. In the mid-1980s, Boeing produced proposals for an enlarged 767, dubbed 767-X, to target the replacement market for first generation wide-bodies like the DC-10. The initial 767-X featured a longer fuselage and larger wings than the existing 767, along with winglets. Later versions of the proposed 767-X expanded the fuselage cross-section but retained the existing 767 flight deck, nose, and other elements.

Airline customers were unimpressed with the 767-X proposals and instead wanted an even wider fuselage cross-section, fully flexible interior configurations, short to intercontinental-range capability, and an operating cost lower than any 767 stretch. Airline planners' requirements for larger aircraft had become increasingly specific, adding to the heightened competition among aircraft manufacturers. By 1988, Boeing realized that the only answer was a new design, which would become the 777 twinjet. On December 8, 1989, Boeing began issuing offers to airlines on its proposed new wide-body aircraft.

Design effort

The Boeing 777 design phase was different from the company's previous commercial jetliners. For the first time, eight major airlines, namely All Nippon Airways, American Airlines, British Airways, Cathay Pacific, Delta Air Lines, Japan Airlines, Qantas, and United Airlines, had a role in the development of the airliner. This was a departure from industry practice, where manufacturers typically designed aircraft with little airline input. The eight airlines that contributed to the 777 design process became known within Boeing as the "Working Together" group. At the first group meeting in January 1990, a 23-page questionnaire was distributed to the airlines, asking each what it wanted in the new design. By March 1990, Boeing and the airlines had decided upon a basic design for the 777: a cabin cross-section close to the 747's, capacity up to 325 passengers, fly-by-wire controls, a glass cockpit, flexible interior, and 10% better seat-mile costs than the A330 and MD-11.

In October 1990, United Airlines became the Boeing 777's launch customer when it placed an order for 34 Pratt & Whitney-powered 777s with options on a further 34. The development of the 777 coincided with United's replacement program for its aging DC-10s. United required that the new aircraft be capable of flying three different routes: Chicago to Hawaii, Chicago to Europe, and non-stop from Denver, a hot and high airport, to Hawaii. ETOPS certification was also a priority for United, given the overseas portion of United's Hawaii routes.

By January 1993, Boeing had formally designated its new airliner as the 777, and a team of United 777 developers joined other airline teams and Boeing designers at the Boeing Everett factory in Washington. Divided into 240 design teams of up to 40 members, working on individual components of the aircraft, almost 1,500 design issues were addressed. The fuselage diameter was further increased to suit Cathay Pacific, the baseline model grew longer for All Nippon Airways, and British Airways' input led to added built-in testing and interior flexibility.

The Boeing 777 was the first commercial aircraft to be designed entirely on computer. All design drawings were created on a 3D CAD software system known as CATIA, sourced from Dassault Systemes and IBM. This allowed a virtual 777 to be assembled, in simulation, to check for interferences and to verify proper fit of the many thousands of parts, thus reducing costly rework. Boeing was initially not convinced of the program's abilities and built a physical mock-up of the nose section to verify the results. The test was so successful that all further mock-ups were cancelled.

Production and testing

The production process for the Boeing 777 included substantial international content, with an unprecedented level of global subcontracting for a Boeing jetliner, exceeded only by the later 787. International contributors included Mitsubishi Heavy Industries and Kawasaki Heavy Industries (fuselage panels), Fuji Heavy Industries, Ltd. (center wing section), Hawker de Havilland (elevators), and Aerospace Technologies of Australia (rudder). An agreement between Boeing and the Japan Aircraft Development Corporation, representing Japanese aerospace contractors, made the latter risk-sharing partners for 20% of the entire 777 program. The 777 was launched with propulsion options from three manufacturers, Pratt & Whitney, General Electric, and Rolls-Royce, giving the airlines their choice of engines from competing firms.

Boeing selected its Everett factory, home of 747 production, as the site of 777 final assembly. To accommodate production of its new twinjet, Boeing doubled the size of the Everett factory at the cost of nearly US$1.5 billion to provide room for the addition of two new 777 assembly lines. Among new production methodologies developed for the 777, Boeing developed a turn machine which could rotate fuselage subassemblies 180 degrees, allowing workers access to 777 upper body sections. Production of the first 777 prototype began in January 1993. By the start of 777 production, the program had amassed 118 firm orders, with options for 95 more from ten airlines. Total investment in the 777 program was estimated at over US$4 billion from Boeing, with an additional US$2 billion from suppliers.

On April 9, 1994, the first Boeing 777, line number WA001, was rolled out in a series of fifteen ceremonies held during the day to accommodate the 100,000 invited guests. The first flight took place on June 12, 1994, piloted by 777 Chief Test Pilot John E. Cashman. This marked the start of an eleven month flight test program which was intended to be more extensive than that of any previous Boeing model. Nine aircraft in total were used in 777 flight testing, five powered by Pratt & Whitney PW4000 engines, two by General Electric GE90 engines, and two by Rolls-Royce Trent 800 engines. Testing locations included the desert airfield at Edwards Air Force Base in California and frigid conditions in Alaska. To satisfy ETOPS requirements, eight 180-minute single-engine diversion test flights were performed. The first 777-200 built was used by Boeing's nondestructive testing campaign in 1994–1995, and provided data for the -200ER and -300 programs. At the successful conclusion of flight testing, the 777 was awarded simultaneous airworthiness certification by the Federal Aviation Administration (FAA) and Joint Aviation Authorities (JAA) on April 19, 1995.

Entry into service

On May 15, 1995, Boeing delivered the first 777, registered N777UA, to United Airlines. The FAA awarded 180-minute ETOPS clearance ("ETOPS-180") for Pratt & Whitney PW4084 engined 777-200s on May 30, 1995, making the 777 the first aircraft to carry an ETOPS-180 rating at its entry into service. Longer ETOPS clearance of 207 minutes was approved later. The Boeing 777's first commercial flight took place on June 7, 1995, from London's Heathrow Airport to Dulles International Airport near Washington, D.C..

In November 1995, Boeing delivered the first 777 with General Electric GE90-77B engines to launch customer British Airways, which subsequently placed the aircraft into service later that month. Initial service with the engine was affected by gearbox bearing wear issues, which caused British Airways to temporarily withdraw its GE90-77B engined aircraft from transatlantic service in 1997. British Airways' GE90-77B-engined 777s returned to full service later that year, and engine manufacturer General Electric subsequently announced upgraded GE90 versions.

The first Rolls-Royce Trent 877-powered Boeing 777 was delivered to Thai Airways International in March 1996, completing the entry of all three 777 powerplants into service. All three 777 engine-airframe combinations had secured ETOPS-180 certification from the point of entry into service. By June 1997, total orders for the 777 numbered 323 from 25 customers, including satisfied launch customers which had ordered additional aircraft. Performance data from 777 operations established the consistent capabilities of the twin-engine airliner over long-haul transoceanic routes, leading to further sales. By 1998, dispatch reliability rates (measuring takeoff without delay) for the Boeing 777 had reached 99.96% as 777 operations grew, and total fleet hours approached 900,000.

Further developments

After the initial 777-200 model, Boeing developed the 777-200ER, an increased gross weight variant, which first flew on October 7, 1996. The 777-200ER received FAA and JAA certification on January 17, 1997, and entered service with British Airways in February 1997. Offering greater range and payload capability, the 777-200ER subsequently became the most popular version of the 777 in service. On April 2, 1997, a Malaysia Airlines Boeing 777-200ER dubbed "Super Ranger" broke the great circle "distance without landing" record for an airliner by flying eastward from Boeing Field, Seattle, to Kuala Lumpur, Malaysia, a distance of 10,823 nautical miles (20,044 km), in 21 hours, 23 minutes.

Following the introduction of the 777-200ER, Boeing turned its attention to a stretched variant of the 777. On October 16, 1997, the first 777-300 made its first flight. At 242.4 ft (73.9 m) in length, the 777-300 became the longest airliner yet produced (until the A340-600), and had a 20% greater overall capacity than the standard 777-200. On May 4, 1998, the 777-300 was awarded type certification simultaneously from the FAA and JAA, and granted 180-minute ETOPS approval. The 777-300 entered service with launch customer Cathay Pacific later that month.

By the late 1990s, Boeing was considering ultra-long-range versions of the 777-200 and 777-300. A more powerful engine was required, leading to active discussions between Boeing and the 777 engine manufacturers. General Electric offered to develop the GE90-115B engine, with a projected thrust of 115,000 lbf (510 kN), while Rolls-Royce proposed developing the Trent 8104 engine, with a thrust of 104,000 to 114,000 lbf (460 to 510 kN). In 1999, Boeing announced an agreement with General Electric, beating out proposals from Rolls-Royce and Pratt & Whitney. As part of the deal with General Electric, Boeing agreed that GE90 engines would be the only engines offered on new long-range 777 models.

Next-generation 777s

In February 2000, Boeing began issuing offers to airlines on its next-generation long-range 777 program, initially called 777-X. Development of the next-generation 777s was slowed by the airline industry downturn, which lasted through the early 2000s. The first model to emerge from the 777-X program, the 777-300ER, was launched with an order for ten aircraft from Air France, along with additional undisclosed orders. The first flight of the 777-300ER occurred on February 24, 2003, and FAA and European Aviation Safety Agency (EASA, successor to the JAA) certification was achieved on March 16, 2004. The first delivery to Air France took place on April 29, 2004. The 777-300ER, which combined the -300's added capacity with the -200ER's range, became the top-selling 777 variant, with orders benefiting as airlines replaced comparable four-engine models with twinjets because of their lower operating costs.

The second model to originate from the 777-X program, the 777-200LR, rolled out on February 15, 2005, and completed its first flight on March 8, 2005. The -200LR was certified by both the FAA and EASA on February 2, 2006, and the first delivery to Pakistan International Airlines occurred on February 26, 2006. On November 10, 2005, the first 777-200LR set a record for the longest non-stop flight by a passenger airliner by flying 11,664 nautical miles (21,602 km) eastward (the westerly great circle route is only 5,209 nautical miles) from Hong Kong to London. The flight took 22 hours and 42 minutes, with airline representatives and media guests on board. The event was logged into the Guinness World Records and surpassed the 777-200LR's design range of 9,380 nautical miles (17,370 km).

By 2007, sales of the next generation 777 family, composed of the 777-200LR and 777-300ER, approached 350 aircraft. In November 2007, Boeing announced that all 777 production was sold out to 2012. In May 2008, Boeing introduced the first 777 Freighter, the 777F, based on the structural upgrades and engine specifications of the 777-200LR, with fuel tanks derived from the 777-300ER.

By 2008, the 777 faced the possibility of increased competition from Airbus' planned A350 XWB and internally from proposed variants of the 787, both airliners that promise further fuel efficiency improvements. According to industry reports, the current 777 may eventually be replaced by a new product family, the Boeing Yellowstone 3, which would draw upon technologies from the 787.

Design

Boeing introduced a number of advanced technologies with the 777 design, including fully digital fly-by-wire (electrically, rather than mechanically operated) flight controls, fully software-configurable avionics, Honeywell LCD glass cockpit flight displays, and the first use of a fiber optic avionics network on a commercial airliner. Boeing made use of work done on the cancelled Boeing 7J7 regional jet, which utilized similar versions of the chosen technologies. In 2003, Boeing further began offering the option of electronic flight bag computer displays in 777 cockpits.

Fly-by-wire

In designing the 777 as its first fly-by-wire commercial aircraft, Boeing decided to retain conventional control yokes rather than fit sidestick controllers as used in many fly-by-wire fighter aircraft and in some Airbus transports. Along with traditional yoke and rudder controls, the cockpit features a simplified layout which retains similarities to previous Boeing models. The 777 fly-by-wire system also incorporates flight envelope protection, a system which guides pilot inputs within a computer-calculated framework of operating parameters, acting to prevent stalls and overly stressful maneuvers. This system can be overridden by the pilot in command if deemed necessary.

Airframe

The 777 wing employs a supercritical airfoil design that is swept back at 31.6 degrees and optimized for cruising at Mach 0.83 (revised upward after flight tests to Mach 0.84). The wing was designed with increased thickness and a longer span than previous airliners, resulting in improved payload and range, improved takeoff performance, and a higher cruising altitude. Folding wingtips were offered when the 777 was launched, to appeal to airlines who might use the aircraft in gates made to accommodate smaller aircraft, but no airline purchased this option.

The 777's airframe incorporates the use of composite materials, which comprise nine percent of its original structural weight. Elements made from composite material include the cabin floor and rudder. The main fuselage cross-section is circular and tapers aftward into a blade-like tail cone with a port-facing auxiliary power unit. The 777 also features the largest landing gear and the biggest tires ever used in a commercial jetliner. Each main gear tire of a 777-300ER can carry a load of 59,490 lb (26,980 kg), heavier than other wide-bodies such as the 747-400.

Interior

The interior of the Boeing 777, also known as the Boeing Signature Interior, features curved panels, larger overhead bins, and indirect lighting. Seating options range from six abreast in first class up to 10 across in economy. The 777's 15 in (380 mm) by 10 in (250 mm) windows are the largest of any current commercial airliner. The 777 cabin features "Flexibility Zones", which entails deliberate placement of water, electrical, pneumatic, and other hook-ups throughout the cabin space, allowing airlines to move seats, galleys, and lavatories quickly when adjusting cabin arrangements.

After its introduction on the 777, the Signature Interior has been used on other Boeing wide-bodies (747-400ER, 767-400ER, newer 767-300ERs, and newer -200ERs), and adapted for narrow-bodies (737NG, 757-300), along with larger 777-style windows (747-8, 767-400ER).

In 2003, Boeing introduced overhead crew rests as an option on the 777. Located above the main cabin and connected via staircases, the forward flight crew rest contains two seats and two bunk beds, while the aft cabin crew rest features multiple bunk beds. The 777 has also been fitted with VIP interiors for non-airline use.

Variants

Boeing uses two characteristics, fuselage length and range, to define their 777 models. Fuselage length affects the number of passengers and amount of cargo that can be carried; the 777-200 and derivatives are the base size, and the aircraft was stretched into the 777-300 in 1998. In terms of range, the 777 has been categorized into three segments based on initial design criteria as follows:

When referring to variants of the 777, Boeing and airlines often collapse the model (777) and the capacity designator (200 or 300) into a smaller form, such as "772" or "773". The International Civil Aviation Organization (ICAO) aircraft type designator system uses a similar format, but adds a preceding letter to designate the manufacturer, such as "B772" or "B773". Subsequent to the capacity number, designations may or may not append the range identifier. For example, the 777-300ER may be referred to as a "773ER", "773B", "77W", or "B77W". Any of these notations may be found in aircraft manuals or airline timetables.

Initial models

777-200

The 777-200 (772A) was the initial A-market model. It is available with a maximum takeoff weight (MTOW) of 545,000 lb (247,000 kg) and range capability of 5,235 nautical miles (9,695 km). The -200 is powered by 77,000 lbf (340 kN) PW4077 or GE90-77B, or 76,000 lbf (340 kN) Trent 877 turbofans. A total of 88 -200s have been delivered to ten different customers, and 86 -200s were in airline service as of July 2008. Competing aircraft from Airbus include the A330-300.

777-200ER

The 777-200ER ("ER" for Extended Range) was originally known as the 777-200IGW (for "increased gross weight") and 777B (referring to its range market). The 777-200ER features additional fuel capacity, with increased MTOW from 580,000 to 631,000 lb (260,000 to 290,000 kg). Range capability is 7,700 nautical miles (14,300 km). Engines offered for the 777-200ER include the 94,000 lbf (420 kN) GE90-94B, 90,000 lbf (400 kN) PW4090, and 93,000 lbf (410 kN) Trent 895.

The first 777-200ER, powered by 84,000 lbf (370 kN) GE90-85B engines, was delivered to British Airways in February 1997. The Trent 800 and PW4000 series engines have since become the most common 777-200ER powerplants, with the Trent 800 having approximately 25% market share among all 777 variants.

In addition to breaking the eastbound great circle "distance without landing" record, the 777-200ER also holds the record for the longest ETOPS-related emergency flight diversion (177 minutes under one engine), on a United Airlines flight carrying 255 passengers on March 17, 2003, over the Pacific Ocean. As of May 31, 2009, 410 777-200ERs had been delivered to 33 different customers with 23 unfilled orders, and 397 -200ER aircraft were in airline service as of July 2008. The competing aircraft from Airbus is the A340-300.

777-300

The stretched A-market 777-300 (773A) was designed as a replacement for 747-100s and -200s. Compared to the older 747s, the stretched 777 has comparable passenger capacity and range, and is designed to burn one-third less fuel and have 40% lower maintenance costs. The 777-300 features a 33.3 ft (10.1 m) fuselage stretch over the baseline 777-200, allowing seating for up to 550 passengers in a single class high-density configuration. The 777-300 is also 29,000 lb (13,000 kg) heavier, and due to the aircraft's length, is equipped with a tailskid and ground maneuvering cameras (mounted on the horizontal tail and underneath the forward fuselage) to aid pilots during taxi. The maximum operating range is 6,015 nautical miles (11,140 km). The 777-300 is powered by the following engines: 90,000 lbf (400 kN) PW4090, 92,000 lbf (410 kN) Trent 892 or GE90-92B, or 98,000 lbf (440 kN) PW4098 turbofans.

Since the debut of the 777-300, a total of 60 -300s have been delivered to eight different customers, and all were in airline service as of July 2008. However, following the introduction of the longer range -300ER in 2004, all operators have selected the ER version of the -300 model. The 777-300 has no direct Airbus rival, but the A340-600 is offered in competition.

Longer range models

777-200LR

The 777-200LR (772C) ("LR" for Longer Range) became the world's longest range commercial airliner when it entered service in 2006. Boeing named this aircraft the Worldliner, highlighting its ability to connect almost any two airports in the world, although it is still subject to ETOPS restrictions. It holds the world record for the longest nonstop flight by a commercial airliner, at a distance of 11,664 nautical miles (21,602 km). In regular service, the -200LR is capable of flying 9,380 nautical miles (17,370 km). Developed alongside the 777-300ER, the -200LR uses either 110,000 lbf (490 kN) thrust GE90-110B1 turbofans or, as an option, the GE90-115B turbofans used on the -300ER. The -200LR features a significantly increased MTOW to 766,000 lb (347,000 kg) and three optional auxiliary fuel tanks in the rear cargo hold with a capacity of 5,550 US gallons (21,000 L). Other new features include raked wingtips, a new main landing gear, and additional structural strengthening.

The 777-200LR was preceded by a 777-100X proposal, which would have been a shortened version of the 777-200 analogous to the 747SP. The shorter fuselage would have reduced the empty weight, thus increasing the range. Compared to existing 777 models, however, the aircraft would have carried fewer passengers while having similar operating costs, leading to a higher cost per seat. With the advent of more powerful engines, the 777-100X was supplanted by the 777-X program, which evolved into the -200LR.

The 777-200LR first entered service with Pakistan International Airlines in February 2006 and through May 31, 2009, had received orders from Air Canada, Emirates, Qatar Airways, Delta Air Lines, Turkmenistan Airlines, and Air India. By July 2008, 19 -200LRs were in airline service. As of May 31, 2009, 32 777-200LR aircraft had been delivered to six different customers, with 19 unfilled orders. The closest competing aircraft from Airbus is the A340-500HGW.

777-300ER

The 777-300ER ("ER" for Extended Range) is the long range version of the 777-300 and contains many modifications, including 115,300 lbf (513 kN) thrust GE90-115B engines, raked wingtips, a new main landing gear, and extra fuel tanks adding up to 2,600 US gallons (9,800 L) of fuel. Other features include a strengthened fuselage, wings, empennage, nose gear, engine struts and nacelles, and a higher MTOW, 775,000 lb (352,000 kg) versus 660,000 lb (300,000 kg) for the 777-300. The maximum range is 7,930 nautical miles (14,690 km). The 777-300ER's GE90-115B turbofans are the world's most powerful jet engines in service.

The 777-300ER's extra 1,935 nautical miles (3,584 km) range over the 777-300 is mainly due to the increase in the MTOW, along with the increased maximum fuel capacity from 45,220 US gallons (171,200 L) to 47,890 US gallons (181,300 L). The -300ER weighs slightly more than the -300, and has engines that produce more thrust, which allow the -300ER to fly approximately 34% farther with a full load of passengers and cargo. During flight testing, the 777-300ER demonstrated a 2% better fuel burn than expected, and further engine, wing, and weight modifications produced an added 1.4% reduction in fuel consumption. Early 777-300ER customers ordered modification kits to incorporate these enhancements to in-service aircraft.

The first 777-300ER was delivered to Air France in April 2004. Along with Air France, the 777-300ER has been acquired as a primary long-haul aircraft of major airlines including All Nippon Airways, Cathay Pacific, Emirates, and Singapore Airlines. By 2005, with the 777-300ER leading its sales, the 777 had outsold the rival A340. Although the 777-300ER's GE90-115B engine burns more fuel individually versus the A340-600's Trent 556 engine, using only two engines produces a typical operating cost advantage of around 8-9% for the 777-300ER.

The 777-300ER also has a typical fuel burn advantage of 20% per trip versus the four-engined 747-400, leading airlines such as Air New Zealand, British Airways, and Japan Airlines to acquire the aircraft as a 747 replacement. As fuel prices rise and airlines look to cut expenses while keeping their higher margin customers, operators have retained premium seating and reduced economy capacity when replacing the 416-seat 747-400 with the 365-seat 777-300ER. By July 2008, 147 777-300ERs were in airline service. As of May 31, 2009, a total of 188 -300ERs had been delivered to 19 different customers, with 215 unfilled orders. The 777-300ER's direct Airbus competitor is the A340-600HGW.

777 Freighter

The 777 Freighter (777F) is an all-cargo version of the 777-200LR. It amalgamates features from the 777-200LR and the 777-300ER, using the -200LR's structural upgrades and 110,000 lbf (490 kN) GE90-110B1 engines, combined with the fuel capacity of the -300ER. The 777F was officially launched on May 23, 2005, following a launch order from Air France-KLM for five aircraft. The 777F was officially unveiled in an rollout ceremony at the Everett factory on May 21, 2008, two days after a photo of the fully-painted aircraft was released. The 777F made its maiden flight on July 14, 2008, and received FAA and EASA type certification in February 2009. Air France took delivery of the first 777F on February 19, 2009.

With a maximum payload of 226,000 lb (103,000 kg), the 777F's capacity is similar to the 243,000 lb (110,000 kg) of 747 freighters, with a nearly identical payload density. Customers have targeted the 777F as a replacement for older freighters such as the 747-200F, as the 777F promises improved operating economics compared to existing 220,000+ lb (100,000+ kg) payload freighters. With the same fuel capacity as the 777-300ER, the 777F has a range of 4,885 nautical miles (9,047 km) at maximum payload, although greater range will be possible if less weight (lower density, emphasizing volume) is carried. The 777F is also targeted as a direct replacement of the rival MD-11F.

The 777F's largest customer, FedEx Express, placed its first order for 15 777Fs with 15 options on November 7, 2006, following the cancellation of its Airbus A380-800F order due to delivery delays. In January 2009, FedEx exercised its options on 15 more 777Fs and took a further 15 options for the freighter. A total of 72 777Fs were on order with four deliveries as of April 30, 2009.

777 Tanker (KC-777)

The KC-777 is a proposed tanker version of the 777. In September 2006, Boeing publicly announced that it was ready and willing to produce the KC-777, if the United States Air Force (USAF) requires a bigger tanker than the KC-767. In addition the tanker would be able to transport cargo or personnel. In April 2007, Boeing instead offered its KC-767 Advanced Tanker for USAF's KC-X competition.

Incidents and accidents

As of May 2009, the Boeing 777 has been in seven incidents, including one hull-loss accident, with no fatalities among the passengers or crew. The only fatality involving a Boeing 777 occurred in a refueling fire at Denver International Airport on September 5, 2001, during which a ground worker sustained fatal burns. The aircraft, operated by British Airways, suffered scorching of the wings and was repaired and put back into service.

The type's first hull loss occurred on January 17, 2008, when British Airways Flight 38, a Rolls-Royce Trent 895 engined 777-200ER flying from Beijing to London, crash-landed approximately 1,000 feet (300 m) short of Heathrow Airport's runway 27L and slid onto the runway's threshold. There were thirteen injuries and no fatalities. The impact damaged the landing gear, wing roots, and engines, and the aircraft was written off. Upon investigation, the accident was blamed on ice crystals from the fuel system clogging the fuel-oil heat exchanger. Air accident investigators called for this component on the Trent 800 series engine to be redesigned, and manufacturer Rolls-Royce said the new part should be ready within a year.

On February 28, 2008, American Airlines Flight 299 from Miami to Los Angeles, a 777-200ER fitted with Rolls-Royce Trent 895 engines experienced a momentary loss of thrust with one engine on final approach, with normal operations resuming thereafter.

On November 26, 2008, Delta Air Lines Flight 18 from Shanghai to Atlanta, also a 777-200ER with Rolls-Royce Trent 895 engines, experienced an uncommanded reduction in thrust of one engine while in cruise at 39,000 feet (12,000 m). The crew descended to 31,000 feet (9,400 m) and followed manual recovery procedures, with the flight continuing without further incident. The National Transportation Safety Board (NTSB) investigators concluded that, just as on British Airways Flight 38, the loss of power was caused by ice in the fuel clogging the fuel-oil heat exchanger. Although pilot work-arounds now exist, the NTSB also requested a re-design of the heat exchanger.

Specifications

Sources: Boeing 777 specifications, Boeing 777 Airport planning report, Civil Aircraft, Rolls-Royce Trent 800 series data
Note: *Preliminary range for aircraft only just into service.

Operators

The customers that have received the most 777s are ILFC, Emirates, Singapore Airlines, and United Airlines. A total of 714 Boeing 777 aircraft (all variants) were in airline service as of July 2008, with Singapore Airlines (75), Emirates (59), United Airlines (52), Air France (51), American Airlines (47), All Nippon Airways (42), British Airways (42), Japan Airlines (40), Cathay Pacific (25), Saudi Arabian Airlines (23), Korean Air (21), Malaysia Airlines (17), Air Canada (14), and other operators with fewer aircraft of the type.