Boeing 777 'Triple Seven'

Boeing 777

The Boeing 777 'Triple Seven' comprises a family of large twin-engined widebody airliners. They fly 300 to 400 passengers over medium to ultra-long distances.

Boeing started the development of the 777 in the late 1980s as a stretched version of the 767 with the intention to fill the capacity-'gap' between the 767-300 and the 747-400. The new version was provisionally designated '767-X', but the airlines didn't show enthusiasm for it. Therefore Boeing switched to an all-new design with a wider fuselage. The first Boeing 777 made its maiden flight on 12 June 1994. Boeing delivered the first production aircraft to United Airlines in May 1995 and the airline introduced it on its Denver to Chicago O'Hare service on 7 June 1994, soon followed by the first international flight between Washington Dulles and London Heathrow.

The 777 was the first airliner completely designed with a computer aided design (CAD) system. This system eliminates the need to build an expensive full-size mock-up of the aircraft, which is usually made to prevent the misfits of parts during the development phase. The computer has a major role too in the cockpit, which was designed for two-man operation and features six liquid crystal displays (LCDs) to present flight data to the crew. The 777 was the first Boeing airliner with a full fly-by-wire control system. The airframe consists of 10 percent composite materials (by weight).

Engines

Boeing offered the 777 with engine options from all three major turbofan manufacturers: the Pratt & Whitney PW4084, the Rolls Royce Trent 895 and the General Electric GE90. In May 1995 the Federal Aviation Administration granted the 777 full 180 minutes ETOPS (Extended-Range Twin-Engine Operations) clearance to allow it to fly long over-water or desert sectors up to 180 minutes flying time on a single engine from the nearest diversion airport.

Initially Boeing developed two versions: the standard 777-200 and the 777-200IGW (Increased Gross Weight - later renamed 777-200ER) with higher weights and extended range. The first flight of the 777-200ER was on 7 October 1996 and British Airways became the first user in 1997.

The 777-200LR (Longer Range), named 'Worldliner', has an even much more extended range and higher take-off weights. This version can stay up to 18 hours in the air and with a range of 17,500 km (9,450 nm) it is the world's airliner with the 'longest legs'. Like the 777-300ER it has raked wingtips, additional fuel capacity and a new main landing gear. The aircraft's structure is strengthened to enable it to carry heavier weights.

The Worldliner performed its maiden flight on 8 March 2005 and the first example was delivered to PIA Pakistan International Airlines in February 2006. A 777-200LR performed a world record flight for distance travelled nonstop by a commercial airliner on 9 and 10 November 2005 from Hong Kong to London Heathrow over 21,601 km (11,664 nm). That is more than halfway around the world. The flight lasted 22 hours and 42 minutes.

777-300

A 10.13m (33ft 3in) stretched version is the 777-300, which was intended as a replacement for early generation Boeing 747s, offering almost the same passenger capacity and range but much lower fuel burn and lower maintenance costs. The 777-300 can seat up to 550 passengers in a high-density cabin layout. Compared with the 777-200 it has a strengthened undercarriage, airframe and inboard wing. Boeing also added a tailskid to prevent tail-strikes on takeoff and landing, and mounted ground manoeuvring cameras on the horizontal tail and underneath the forward fuselage. Further changes were kept minimal for the sake of commonality with the 777-200. The first flight of the 300 was on 16 October 1997 and the aircraft was simultaneously certificated by the US FAA and the European JAA on 4 May 1998. The first 777-300 was delivered to Cathay Pacific the same month.

Extended Range

The most successful 777-version is the 777-300ER (Extended Range), which first flew on 24 February 2003 and of which Air France took the first delivery on 29 April 2009. The 300ER has extended, raked wingtips, a new main landing gear, a reinforced nose gear, and extra fuel tanks. Many parts of the airframe are strengthened to carry the heavier loads, like the fuselage, the empennage and the engine pylons. Boeing offers only one engine option: the GE90-115B turbofan, the world's most powerful jet engine in service.

Many 777-300ERs replace the later 747-models. Airports with much long-haul traffic once dominated by 747s, are now visited by large numbers of 777-300ERs instead. The 777-300ER competed successfully with the four-engined Airbus A340-500 and A340-600. Airlines preferred the lower operating costs of the twin-engined 777 and Airbus stopped production of the A340. Airbus is more successful with the all-new A350 of which the biggest planned version, the A350-1000, is a little smaller than the 777-300ER.

777F

A freighter version, the 777F, flew for the first time on 14 July 2008. It is based on the 777-200LR airframe and it entered service with launch customer Air France on 19 Febuary 2009. The 777F was developed as a replacement for the Boeing 747-200F, the MD-11F and the DC-10F.

777-X

At the Dubai Airshow 2013 Boeing officially launched the 777-X, which includes two new models: the 777-8X and 777-9X (Image: Boeing). They will have new engines, a composite wing and technologies derived from the 787 Dreamliner. Like the 787 the 777-X will have larger cabin windows than older airliners, increased cabin pressure equivalent to 6,000 feet (1,800 m) altitude and higher humidity for more passenger comfort. The fuselage remains being built of aluminium, however. The 777-8X replaces the 777-200ER and the 777-9X is intended as the successor of the 777-300ER. Both versions have fuselages a little longer than their forebears. Among the first customers are Lufthansa, Emirates Airline, Qatar Airways and Cathay Pacific. Because of problems with the General Electric GE9X engines, the first flight of the 777-9X is postponed for a year until 2020. Boeing delayed the development of the 777-8X until a later, not specified date.

Enhanced

Until the 777-X takes over, Boeing still has to sell and build hundreds of aircraft to keep the production running until 2020. To keep airlines interested in the 'old' versions, the manufacturer will improve these, especially the 777-300ER. The Enhanced 777-300ER offers a 2 per cent reduction in fuel burn and interior reconfigurations result in ten to fourteen extra seats. Other improvements include weight reductions, removal of the tail skid, less cabin noise, the introduction of composite galleys and space-saving lavatories. Production cuts were unavoidable, however, from 8.3 aircraft a month in 2015 down to five a month in 2017.

Until late 2017, around 1,950 Triple Sevens of all versions have been sold. Boeing has delivered all ordered aircraft of the 777-200 versions: 88 777-200s, 422 777-200ERs, and 59 777-200LRs. Of the 777-300 60 were built. Currently in production are the 777-300ER, which is the most successful version, and the 777F. Until late 2017, Boeing has sold 825 300ERs and 161 777 Freighters. The 777X sold well over 300 aircraft so far, with the 777-9 as the most popular version.

Boeing 777-200ER Specifications

Wingspan: 60.93 m (119 ft 11 in). Length: 63.73 m (209 ft 1 in). Height: 18.51 m (60 ft 9 in).
Empty weight: 142,900 kg (315,000 lb). Max. take-off weight: 297,550 kg (656,000 lb).
Accommodation: 301-440 passengers. Range: 14.260 km (7,700 nm). Cruise speed: 905 km/h (490 kts).
Engines: two Pratt & Whitney PW4090 (400 kN - 90,100 lb) or Rolls-Royce Trent 895 (420 kN - 95,000 lb) or General Electric GE90-94B (410 kN - 94,000 lb).

Boeing 777-300ER Specifications

Wingspan: 64.8 m (212 ft 7 in). Length: 73.86 m (242 ft 4 in). Height: 18.70 m (61 ft 5 in).
Empty weight: 166,881 kg (366,940 lb). Max. take-off weight: 357,534 kg (775,000 lb).
Accommodation: 365 passengers (3-class). Range: 14,685 km (7,930 nm). Cruise speed: 905 km/h (490 kts).
Engines: two General Electric GE90-115B (512 kN - 115,300 lb).

Boeing 777F Freighter Specifications

Wingspan: 64.8 m (212 ft 7 in). Length: 63.73 m (209 ft 1 in). Height: 18.6 m (61 ft 1 in).
Empty weight: 144,400 kg (318,300 lb). Max. take-off weight: 347,800 kg (766,800 lb).
Range: 9,070 km (4,900 nm). Cruise speed: 905 km/h (490 kts).

Engines: two General Electric GE90-115B (512 kN - 115,300 lb).

Boeing 777-8 Specifications

Wingspan: 71.8 m (235 ft 5 in) (Folded: 64.8 m (212 ft 9 in)). Length: 69.8 m 229 ft 0 in). Height: 19.5 m (64 ft 0 in).
Max. take-off weight: 351,534 kg (775,000 lb). Passengers: 365 (2-class). Range: 16.110 km (8,700 nm). Engines: two General Electric GE9X-105B1A (470 kN - 105,000 lbf).

Boeing 777-9 Specifications

Wingspan: 71.8 m (235 ft 5 in) (Folded: 64.8 m (212 ft 9 in)). Length: 76,7 m 251 ft 9 in). Height: 19.7 m (64 ft 7 in).
Max. take-off weight: 351,534 kg (775,000 lb). Accommodation: 349-414 passengers. Range: 14,075 km (7,600 nm).
Engines: two General Electric GE9X-105B1A (470 kN - 105,000 lbf).