Boeing 747-400 Twin-Aisle Jet Airliner, USA

Boeing originally designed the 747 in the 1960s for the US Air Force's large jet cargo transport programme. The contract went to Lockheed's C5-A Galaxy, so Boeing decided to pursue the commercial aviation market with their new 'jumbo' 747.

The 747 commercial development programme was initiated in 1966 when Boeing received an order from Pan American World Airways for 25 747s. The specification laid down was for a cost-effective intercontinental airliner, capable of carrying high volume passenger traffic whilst retaining a superior level of fuel economy.

On 9 February 1969, the chief test pilot Jack Wadell and crew took the first 747 (registration N7470) into the air.

The first model (747-100) entered commercial service with Pan Am in 1970 and took its maiden flight from New York to London. The 747 brought striking reductions in air travel costs through its still unsurpassed combination of speed, range and capacity. 1,341 Boeing 747 aircraft have been delivered.

BOEING'S EVERETT ASSEMBLY PLANT

The 747 project was a massive undertaking and Boeing erected a facility on the 773ac site at Paine Field, Everett, 30 miles north of Seattle, Washington. The facility initially cost $200m, becoming the world's largest building based on volume.

The Everett facility is an assembly plant rather than a factory. It has its own reservoir to contain runoff and a dedicated rail spur to enable 16,000 suppliers and sub contractors to deliver their six million parts and components to the 747 assembly line.

THE BOEING 747-400 FAMILY

The basic 747-400 series has five models. The passenger model has a maximum range of 8,430 miles (13,570km) in its three-Class 416-seat configuration and has the largest long-haul passenger capability with 524 seats in its two-Class configuration.

The freighter model can carry 124t (113,000kg) of cargo 4,400nm. The domestic model has 568 passenger seats and a range of 1,805nm. The combi model, designed to carry both passengers and freight has 266 seats, seven cargo pallets and a range of 8,300 statute miles.

The first 747-400 model rolled out of Everett in January 1988 and entered commercial service in February 1989 with Northwest Airlines. Boeing cancelled plans for a stretch version, the 747X, in April 2001.

The first of two 747-400ER extended-range models took its maiden flight in July 2002 and was delivered to launch customer Qantas Airways in October 2002. The 747-400ER is available in either passenger or freighter versions with either greater range or payload capacity. With a gross take-off weight of 412,770kg, the passenger version can fly an additional 805km or carry an additional 6,800kg of payload.

The first freighter version was delivered to Air France in November 2002. Other orders for the freighter version include KLM, Korean Air, Cargolux, Cathay Pacific Airways and, in February 2004, Nippon Cargo Airlines.

In November 2005, Boeing launched the 747-8 aircraft, including passenger and freighter versions. The 747-8 will use the GEnx engine, being developed for the 787 Dreamliner, and will have a greater payload, have a longer range of 14,816km (8,000nm) and fly at Mach 0.86.

The passenger version will be extended by 3.6m and carry an additional 34 seats in a three-class, 450-seat configuration. The freighter version will be stretched by 5.6m over the 747-400 freighter and will have a payload capacity of 140t.

Initial orders have been received from Cargolux (ten plus ten options for the 747-8F freighter) and Nippon Cargo (eight freighters). First deliveries are planned for 2009 for the freighter, and 2010 for the passenger version.

In October 2006, Boeing Business Jets launched a VIP version of the 747-8, with an order for three aircraft placed by an undisclosed customer.

FLIGHT DECK

The three-crew analogue flight deck of the 'classic' series has been replaced by a two-crew fully digitised flight deck. Six, 8in x 8in (200mm x 200mm) Cathode Ray Tube (CRT) displays replace the previous electro-mechanical displays.

The CRT displays show the aircraft flight control systems, navigation systems and Engine Indicating and Crew Alerting Systems (EICAS). The CRT displays have built-in redundancy in case of a failure with automatic and manual backup display switching systems.

The 747-400 autopilot, flight direction system and navigation suite is provided by Rockwell Collins, with Honeywell providing the Future Air Navigation System (FANS 1) GPS inertial reference system. Honeywell also provided the flight management computer and digital air data computer. Avionics systems were also provided by Smith Industries (altitude alerting computer and fuel quantity indicators), Parker Aerospace (autobrake control module) and Labinal (tyre pressure indicating system).

The integrated digital avionics systems allowed the Boeing designers to reduce flight deck lights, gauges and switches from 971 in the 747-300 to 365 on the 747-400 model. The digitised flight deck significantly reduce the flight crew workload, with an estimated saving of 33%-50%.

The new 747-400ER is equipped with Rockwell Collins DU-7001 Active Matrix Liquid Crystal Displays (AMLCD).

DESIGN

In order to enhance fuel efficiency the 747-400 wings were redesigned, increasing the wingspan from 195ft 8in (59.6m) to 211ft 5in (64.4m). Additional 6ft-high composite winglets have been added, angled upward and marginally outward from the wing tips. The aerodynamic characteristics of these winglets provide a disproportionately superior lift-to-wing-surface-area effect to the wing as a whole without increasing overall wingspan or drag.

The wing weight was reduced even after the increase in wingspan due to the use of high strength aluminium alloys and composite materials. The winglets give the 747-400 a fuel mileage improvement of 3% and their upward angle means that the overall wingspan remains within the standard airport apron slot.

Aerodynamic improvements to the wing-to-body fairings, engine nacelles and engine struts have been implemented to reduce drag. Boeing's suppliers such as GKN, Daewoo, Fuji Heavy Industries, Parker Aerospace and Yokohama Rubber have enabled airframe weight to be reduced in a number of areas by using composite materials such as graphite-epoxy, special aluminium alloys and honeycomb materials.

Logistics and lifetime maintenance cost have been enhanced in a number of systems and components. The wings and fuselage incorporate high strength aluminium skins with improved fatigue life. Goodrich's structural carbon brakes have improved energy absorption properties and wear resistance and also provide a weight saving on the 16 main landing gear wheels of 1,800lb (816kg).

747-400 CABIN

The interior was designed with flexibility in mind. Operators can make use of 'quick change features' to allow them to rearrange seating, relocate class dividers, lavatory and galley module positions as required. Ceiling and sidewall panels have been contoured to maximise interior space. Interior panels are made with new lightweight laminate materials with thermoplastic properties that give greater fireworthiness and lower smoke and toxicity levels.

Passenger overhead stowage capacity in the 747-400 was increased to 2.95ft³ (0.082m³) per passenger. The air distribution system has five instead of three zones offering greater control of air supply and air conditioning dependent on passenger density.

The aircraft heating, ventilation and air conditioning, lighting and other electrical systems are supplied from the new 1,450hp Auxiliary Power Unit (APU) from Pratt & Whitney Canada, which runs a fuel efficiency saving of 40%.

ENGINES

The 747-400 is powered by four underwing engines. Three engine systems are offered. Operators may choose between four Pratt & Whitney PW4062 turbofan engines, with 63,300lb maximum thrust, four Rolls-Royce RB211-524H turbofan engines, with 59,500lb maximum thrust or four General Electric CF6-80C2B5F turbofan engines, with 62,100lb maximum thrust.

The internal fuel capacity has a maximum stowage of 57,285gal(216,840l) giving a maximum range of 8,430 statute miles and a typical cruise speed of 565mph (910km/h) at 35,000ft.

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