LONG AND WIDE
Updated: Feb 20, 2020
Many great planes started as modifications of another design. For example, the B-24 Liberator of World War ll was derived from Consolidated's experience with flying boats. The Boeing 747 was initially designed as a double-deck narrow body jet, but entered service as a single-deck wide body jetliner with a small upper deck. During this blog we'll follow the development of a revolutionary aircraft, the Boeing 777.
The triple seven story dates back to 1978, when Boeing came up with three aircraft designs to complement the Boeing 747, but also compete with such jetliners as the McDonnell Douglas DC-10, Airbus A300 and the Lockheed L-1011 TriStar. The first design was the Boeing 757 twinjet, which was intended to replace the trijet Boeing 727 in short-to-medium haul markets. The second design was a wide body twinjet, the Boeing 767, which could offer direct competition with the Airbus A300, and finally a trijet, placing Boeing in competition with the A300B4, DC-10 and the L-1011. Both the 757 and 767 entered service as a result of changes in Extended Operations (ETOPS) regulations,which allowed twinjets to be operating on transoceanic flights. The 757 and the 767 were capable aircraft that offered a more efficient alternative to the 747 on flights with less passenger volume. Boeing conducted a study of the trijet concept, after the 757 and 767 entered service, but rejected it due to the success of the twinjet designs.
By 1986 Boeing decided upon a larger derivative of the wide body 767, the 767-X, offering more capacity to compete with the Airbus A330 and A340, as well as the MD-11, an upgraded stretch version of the DC-10. The only problem was the aircraft was not well received by the airlines. After a series of marketing and engineering studies, Boeing decided a totally new plane was necessary to meet the needs of the airlines, requiring an aircraft of intercontinental range, wide body passenger capacity and lower operating costs than the 767.
Begun during a global recession in 1988, Boeing forged ahead with development of the new aircraft. The design phase of the Boeing 777 was handled differently from previous Boeing airliners. Eight major global airlines collaborated with Boeing during the early stages of the 777 design. In 1990 a questionnaire was distributed by the airlines to determine what they wanted from the design. The conclusions were: fly-by-wire controls, a glass cockpit, a capacity of 325 passengers and a 10 % operating cost reduction below that of the A330/ A340 and the MD-11.
The Boeing 777 is a unique plane in a number of respects. It was the first aircraft to be designed by a computer. Each design was performed by an extremely powerful CAD software called CATIA, developed by Dassault Systems and IBM. The CATIA system required eight computer mainframes to run the main software (EPIC). The EPIC software enabled Boeing engineers to visualize and determine if a given component fits together with other parts inside the virtual airplane, as the pieces were designed. This negated the need for using full-size mock ups to see whether the pieces fit together and gave Boeing engineers the capability to correct any mistakes in component designs before production. Another first for the 777, it was Boeing's first aircraft to be fully fly-by-wire. Fly-By-Wire is a flight control system which uses electrical wires instead of mechanical cables to transfer signals from the aircraft surface controls. Fly-By-Wire technology was mated to the Boeing 777 due to the maintenance costs related to rigging cables. The 777 was also equipped with a very advanced computer, which could make many of the same decisions made by a pilot. After much study, Boeing decided to limit computer control, allowing pilot intervention when necessary. The Boeing 777 utilizes some of the biggest engines in commercial aviation-so big you could drive a car through them. Earlier models use the General Electric G90, which offers a thrust of 105,000 ibf. The 777x uses the General Electric GE9 engine, providing 134,400 ibf. Both engines are the largest in the industry. These engines offer about 20% more power than those on the Boeing 747, operating at 40% less fuel cost. The turbofan engines are so efficient, a 777 could fly on one engine if necessary.
In October 1990 United Airlines placed an order with Boeing for 34 777s to be delivered by 1995, with an option to buy 34 more by 1998. Production of the 777 began in 1993 with its first test flight in June 1994. Flown by all of the major global airlines, the Boeing 777 has perhaps the best safety record of any airliner. Cockpit and crew space is greater than previous jetliners, as well as passenger comfort, though the plane can carry from 315 to 340 passengers, 425 on the 777x, whose test flight was on January 25, 2020. The 777x is a slightly longer version of the earlier 777 models, borrowing concepts from the 787 Dreamliner, such as carbon-fiber construction, large cabin windows and a customized interior. The wings of the Boeing 777x are about twenty feet longer than earlier versions, which provide greater fuel capacity. However, the additional twenty feet was too wide for many airport gates, so Boeing equipped the 777x with eleven foot folding wingtips, the first commercial airliner to use them. With a range of 8,000 miles, the 777x may well be the leading edge of a new wave of jetliners.