Boeing 747-400
The Boeing 747-400 is a large, long-range wide-body airliner produced by Boeing Commercial Airplanes, as an advanced version of the original Boeing 747.
The model was first introduced as the Advanced Series 300 was announced at the September 1984 Farnborough Airshow, targeting a 10% cost reduction with more efficient engines and range increase. Northwest Airlines became the launch customer with an order for ten aircraft on October 22, 1985. The first 747-400 was rolled out on January 26, 1988, made its maiden flight on April 29, 1988, received type certification on January 9, 1989, and entered service with Northwest a month later on February 9, 1989.
It retains the 747 airframe, including the 747-300 stretched upper deck, with winglets. The 747-400 offers a choice of improved turbofans: the Pratt & Whitney PW4000, General Electric CF6-80C2 or Rolls-Royce RB211-524G/H. Its two-crew glass cockpit dispenses with the need for a flight engineer. It typically accommodates 416 passengers in a three-class layout over a range with its maximum takeoff weight.
The first -400M combi was rolled out in June 1989. The -400D Domestic for the Japanese market, without winglets, entered service on October 22, 1991. The -400F cargo variant, without the stretched upper deck, was first delivered in May 1993. With an increased MTOW of, the extended range version entered service in October 2002 as the -400ERF freighter and the -400ER passenger version the following month. Several 747-400 aircraft have undergone freighter conversion or other modifications to serve as transports of heads of state, YAL-1 laser testbed, engine testbed or the Spirit of Mojave air launcher. The Dreamlifter is an outsize cargo conversion designed to move Dreamliner components.
With 694 delivered over the course of 20 years from 1989 to 2009, it was the most-delivered 747 variant. Its closest competitors were the smaller McDonnell Douglas MD-11 trijet and Airbus A340 quadjet. It has been superseded by the stretched and improved Boeing 747-8, introduced in October 2011. Beginning in the late 2010s, 747-400 passenger aircraft began being phased out by airlines in favor of long-range, wide-body twinjet aircraft, such as the Boeing 777 and Airbus A350.
Development
Background
Following its introduction in 1969, the Boeing 747 became a major success with airlines and the flying public. As the world's first wide-body jetliner, the 747 enabled significantly higher passenger capacities on long-range routes. Boeing sold over 1,500 747s across all variants, making it the most-produced wide-body jetliner of its era. In 1980, Boeing announced the 747-300, its latest 747 variant featuring greater passenger capacity. This was made possible by making a stretched upper deck, previously an option on the 747-200, a standard feature. The SUD was almost twice as long as the original 747 upper deck. Besides increased capacity, the 747-300 did not offer any increase in range, nor did it include improvements in flight deck technology or construction materials. At the same time, 747s were becoming more costly to operate due to several factors, notably conventional flight control systems, three-person flight crews, and fuel costs.In 1982, Boeing introduced a two-crew glass cockpit, new engines, and advanced materials on its 757 and 767 twinjets. At the same time, combined sales of the 747-100, −200, −300, and 747SP models exceeded 700, but new orders slowed precipitously. The introduction of the 747-300 did little to stem the decline, and itself faced potential competition from more modern designs. As a result, Boeing began considering a more significant upgrade for its largest passenger jet.
By early 1984, company officials had identified five development objectives for the latest 747 upgrade: new technologies, an enhanced interior, a range increase, more efficient engines, and a 10 percent reduction in operating cost. In September 1984, Boeing announced development of the newest 747 derivative, the "Advanced Series 300", at the Farnborough Airshow. On October 22, 1985, the type was officially launched when Northwest Airlines became the first 747-400 customer, with an order for 10 aircraft. Cathay Pacific, KLM, Lufthansa, Singapore Airlines, and British Airways also announced orders several months later, followed by United Airlines, Air France, Malaysia Airlines and Japan Airlines.
Design effort
Seven early customers, namely British Airways, Cathay Pacific, KLM, Lufthansa, Northwest, Qantas and Singapore Airlines, formed a consultative group to advise Boeing on the 747-400's design process. While the aircraft was planned as a new-technology upgrade, Boeing originally proposed minimal design changes to reduce development cost and retain commonality with existing models. The airline consultative group sought more advanced changes, including a two-crew glass cockpit. As a result of airline input, the 747-400's new digital cockpit design featured cathode-ray tube display technologies first employed on the 757 and 767. The autopilot was also changed to that of the 757 and 767; on the 747-400 a software update was added to allow an 'altitude intervention' mode.File:Winglet and nav light arp.jpg|thumb|The added canted winglet of South African Airways 747-400
The 747-400's wingspan was stretched by over the Classic 747 through wingtip extensions. For reduced aerodynamic drag, the wings were fitted with tall winglets. Despite the added length, the wings were lighter as a result of new aluminum alloys. The horizontal tail was also redesigned to fit a fuel tank, resulting in a range increase, and the rudder travel was increased to 30 degrees to enhance directional control during crosswind operations and high-speed flight. The landing gear was redesigned with larger wheels and carbon brakes. Internal changes further included a restyled cabin with new materials and updated fittings.
New engines offered on the 747-400 included the Pratt & Whitney PW4056, the General Electric CF6-80C2B1F, and the Rolls-Royce RB211-524G/H. The engines offered lower fuel consumption and greater thrust, along with a full-authority digital engine control which adjusted engine performance for improved efficiency compared with the Classic 747s. A new auxiliary power unit manufactured by Pratt & Whitney Canada was also selected to provide on-ground power for the 747-400, with a 40 percent reduction in fuel consumption compared to previous APU designs.
Production and testing
Final assembly of the first 747-400 began at Boeing's Everett factory, the longtime site of 747 production, in September 1987. More than fifty percent of the aircraft was produced by subcontractors, with major structures, engine nacelles, and sub-assemblies supplied by Northrop, and upper deck fuselage frames from Daewoo. All components were integrated during the final assembly process at the Everett factory. The first aircraft, equipped with PW4056 engines, was completed over the winter months of late 1987. On January 26, 1988, the first 747-400 rolled out at the Everett factory, while the first 737-400 rolled out at Boeing's Renton factory on the same day, marking the first double jetliner rollout in the manufacturer's history. By the time of the rollout, the 747-400 program had amassed more than 100 orders.The 747-400 flew for the first time on April 29, 1988, under the command of test pilot James Loesch and co-pilot Kenneth Higgins. The first flight was six weeks behind schedule, owing to subcontractor delays in supplying components, and extra troubleshooting on the aircraft's electronics systems. The maiden flight took off from Paine Field, site of the Everett factory, and landed at Boeing Field, south of Seattle, after an uneventful 2 hours and 26 minutes. The 747-400's flight test program used the first four aircraft built, one more than the minimum number necessary to certify the aircraft's three engine options. One test aircraft each was fitted with the CF6-80C2B1F and RB211-524G/H engines, while the other two featured PW4056 engines, with the fourth aircraft serving as a backup. Federal Aviation Administration certification was received on January 9, 1989, with Pratt & Whitney PW4000 engines, May 18, 1989, with General Electric CF6-80C2s and June 8, 1989, with Rolls-Royce RB211-524Gs.
As the flight test program proceeded, Boeing encountered problems in the 747-400's production process, leading it to disclose delivery delays of up to one month for the first 20 aircraft built. A primary reason for the delays was the unprecedented complexity of interior configurations offered to airlines, which ranged from lavatory and galley locations to the color shades of cabin warning labels. Coupled with new, relatively inexperienced workers, a lack of veteran technicians, interior configurations needing costly re-work, and integration challenges with the advanced flight deck systems, 747-400 production fell behind schedule. The company managed to resolve early production issues by mid-1989, with the first example airframes of all three engine variants delivered within four months of each other, and overall delays not exceeding several weeks.
Service entry and operations
The first 747-400 was delivered to launch customer Northwest Airlines. This jet became known for an incident in 2002 when, as Northwest Airlines Flight 85, the jet suffered a rudder hardover. N661US was later sold to Delta Air Lines when Northwest merged with it. N661US later became preserved at the Delta Flight Museum. This was the 20th anniversary of the 747-100's first flight. On May 31, 1989, Singapore Airlines operated the first international service using a 747-400, on a flight from Singapore to London.In May 1989, one week before the initial delivery to the 747-400's first European customer, KLM, the Joint Aviation Authorities shocked Boeing by refusing to grant regulatory certification for the aircraft, citing the upper deck cabin floor's resistance to collapse in the event of a sudden decompression. While the manufacturer asserted that the 747-400's cabin floor was no different from the already-certified and in-service 747-300, the JAA maintained that the newer model would have a service life into 2020 and beyond and was thus subject to a newer, more stringent standard which had been updated to reflect the risk of explosive devices. In the days leading up to the first delivery to KLM, negotiations between Boeing, the FAA, and the JAA resulted in a compromise: a temporary operating certificate would be issued for the 747-400, provided that the manufacturer develop a structural retrofit for the aircraft within two years. The last-minute deal allowed KLM and Lufthansa to take delivery of their 747-400s without further delays.
After the first 747-400 deliveries, Boeing began production on more variants of the aircraft. The first 747-400 Combi, able to carry both passengers and freight, was rolled out in June 1989. The 747-400 Domestic, a short-range variant of the aircraft designed for Japanese intra-island services, first flew on March 18, 1991, and entered service with Japan Airlines on October 22, 1991. A cargo variant, the 747-400F, was first delivered in May 1993 to Cargolux. By the end of the 1990s, Boeing was producing four versions of the 747-400.