Boeing 777 Twin-Aisle Twinjet Airliner, USA

The Boeing Commercial Airplanes Group introduced the Boeing 777 family of aircraft in 1989. The aircraft fills the size gap between the Boeing 767 and Boeing 747. Over 1,000 aircraft of the Boeing 777 family have been ordered (by more than 43 customers) since the aircraft entered service in May 1995. The 700th was delivered in March 2008. The aircraft is built at the Boeing plant in Everett, Washington.

Boeing 777 variants

The 777-200 was the first of the family of aircraft in production and entered service in May 1995. It has a range of up to 10,900km and seats a maximum of 440 passengers or between 305 and 328 in a typical three-class configuration. 88 aircraft were delivered and production is complete.

The 777-200ER (extended range) flies the same number of passengers as the 777-200 but to a range of 14,260km. The aircraft has a higher fuel capacity and strengthened wing, fuselage, engine pylons, landing gear and empennage (tail unit). The aircraft first flew in October 1996 and first entered service in February 1997 with British Airways. By August 2008, 439 aircraft had been ordered and 407 delivered.

The Boeing 777-300 is a stretched version of the 777, seating 328 to 394 passengers in a typical three class seating arrangement or 550 passengers in a single economy class arrangement. The 777-300 is the latest derivative of the 777 family and the first aircraft was delivered to Cathay Pacific in May 1998. 60 aircraft were delivered and production is complete.

The 777-300ER (extended range) was launched in February 2000 and first flight took place in February 2003. The 300ER set a maximum take-off weight (MTOW) record for a twin-engine aircraft in May 2003. The aircraft received US and European certification in March 2004 and was delivered in May 2004 to launch customer, Air France. The higher fuel capacity, compared to the 777-300, provided a range of 13,335km with 359 passengers.

Subsequent improvements to engine efficiency and design changes to reduce drag and weight have increased the range to 14,594km (7,880nm). The aircraft is powered by a new, more powerful GE90-115B engine rated at 511kN (115,000lb). New highly tapered raked wingtip extensions have been fitted to reduce take-off field length, climb performance and fuel efficiency.

Boeing has received firm orders for 383 aircraft including: Emirates (40), Singapore Airlines (19), International Lease Finance Corp (25), Jet Airways (ten), Cathay Pacific (30), Air Canada (four), Air France (14), ANA (ten), Etihad (five), EVA (12), GE Capital (14), JAL (13), Pakistan International (three), Air India (15), Philippine Airlines (two), Korean Airlines (ten) and Virgin Blue (six). By August 2008, 160 aircraft had been delivered.

The 777-200LR (long range) Worldliner is an ultra long-range version and is designed to be the longest-range aircraft in the world. The aircraft programme was originally known as the 777-200X and was launched in February 2000. Work on the aircraft was halted in October 2001 but restarted in March 2003. The first flight took place in March 2005.

The range is 17,446km carrying 301 passengers. The aircraft is powered by two 489kN engines, type General Electric GE90-110B.

An additional fuel tank installed in the rear cargo bay brings the fuel capacity to 195,280l. The aircraft will also be fitted with new raked wingtip extensions.

Launch customer is Pakistan International Airlines (PIA), which received the first 777-200LR Worldliner in February 2006. Orders for 47 aircraft have been received including: EVA Airways (three), Air India (eight), Qatar Airways, ILFC (two), Jet Airways (six), Emirates (ten), Air Canada (13) and Air India (eight). By August 2008, 21 aircraft had been delivered.

In November 2005, the 777-200LR Worldliner set a world distance record for a commercial aircraft non-stop flight - 21,601km (11,664nm) from Hong Kong to London Heathrow.

In May 2005, Boeing launched the 777F freighter with an order for five aircraft plus three options from Air France. The freighter will be able to carry a revenue payload of 103t (229,000lb) up to 9,195km (4,965nm). Boeing rolled out the first 777F in May 2008 and the first flight was in July 2008. The first 777 freighter is scheduled for delivery to Air France in the fourth quarter of 2008. 78 orders have been received including: Air Canada (two), Avion Group (four), Emirates (eight), FedEx (15) and GE Capital (eight).

Flight deck

The two-pilot flight deck is fitted with a five-screen electronic flight information system with five, 8in (203mm) colour liquid crystal displays, including two primary flight displays, two navigation displays and an engine indication and crew alerting system (EICAS) display. The central control panel between the two pilots holds three multipurpose control and display units for the aircraft information management system, systems information, flight management functions, thrust control and communications.

A two-bunk flight crew rest area is installed on the port side of the flight deck. An optional installation is a crew rest module in the underfloor section. The crew rest module houses six bunks and occupies the same floor area as a standard 96in cargo pallet.

The aircraft has Boeing's fly-by-wire controls with flight envelope protection and automatic pilot and stabilisation functions.

The fly-by-wire system sends back-driven signals to the pilots' rudder pedals and control columns to provide the pilot with sensory awareness of the activities of the automated systems.

The aircraft has a triple redundant digital autopilot and flight director designed by Rockwell Collins. The BAE Systems (formerly Marconi Avionics) triple digital primary flight computers provide the control limits and flight envelope protection commands. Each of the three primary flight computers contains three different and separately programmed 32-bit microprocessors, a Motorola, Intel and AMD, to manage the fly-by-wire functions.

The Boeing 777 was the first aircraft with an ARINC 629 digital data bus linked to the main and standby navigation systems. The navigation system includes a Honeywell ADIRS air data and inertial reference system with a six-ring laser gyroscope, a Honeywell terrain collision avoidance system (TCAS) and a Honeywell and BAE Systems 12-channel global positioning system. The aircraft is equipped with a Honeywell all colour weather radar.

The aircraft can be fitted with a Honeywell and Racal satellite communications system.

Construction

Boeing manufactures the flight deck and forward section of the cabin, the wing, tail and the engine nacelles. Boeing subcontracts the manufacture of components and systems, which are transported to Boeing for final assembly and tests. Subcontractors include Alenia in Italy, ASTA in Australia, BAE Systems in UK, Bombardier Shorts in UK, Embraer in Brazil, Japanese aerospace companies, Kaman in USA, Korean Air, Northrop Grumman in USA and Singapore Aerospace.

Engines

The aircraft has two pod-mounted turbofan engines below the leading edges of the wings. The General Electric, Pratt & Whitney and Rolls Royce Trent engines are rated at 327kN to 436kN thrust.

The main fuel tanks are installed in the wing torsion box with the reserve and surge tanks on the inboard side of the wing. The fuel capacity of the 777-200 is 117,350l. Smiths Industries supplied the ultrasonic fuel quantity gauge system.

A centre section tank installed in the 777-200ER and the 777-300 increases the fuel capacity to 171,175l. The ultra-long range aircraft, Boeing 777-200LR has additional fuel tanks in the rear cargo hold to bring the total fuel capacity to 195,285l.

Landing gear

The aircraft has retractable tricycle-type landing gear. Measco and Messieur Bugatti developed the main landing gear under a joint agreement, which features six-wheeled bogies. Control of the steering rear axles is automatically linked to the steering angle of the nose gear.

The main landing gear is fitted with Honeywell Carbenix 4000 brakes. Initial activation of the brakes during taxiing applies the brakes to alternate groups of three wheels only in order to minimise wear on the brakes. The nose gear is twin-wheeled and is steerable.