A situation likely to be at least partially resolved come April.Skybolt said:it's a pity no-one has really scanned the archives (Boeing's, for one) to try to extricate an evolutionary line for some airliners flying today.
A situation likely to be at least partially resolved come April.
Its strange but the B747 with 4 wing mounted engines looks OK but the proposed BAC1199 'jumbo' with a raised B747 style cockpit area but 4 tail mounted engines doesn't.hesham said:Good fing my dear Jemiba,
and I have a drawing to Boeing 7X7 with two rear engines mounted.
http://www.boeing.com/news/frontiers/archive/2002/december/i_history.htmlThe new 727 replacement—initially dubbed the 7N7—was a single-aisle aircraft that married the basic 727-200 fuselage with a new high-performance wing and new fuel-efficient, high-bypass engines.
The 7N7 design evolved into a 180-passenger airplane that was able to take advantage of the latest engines and boasted a predicted fuel savings of 35 percent per seat. (Inservice fuel savings later proved to be 43 percent.)
This gave Boeing enough confidence in the design to give the 7N7 a place in the Boeing family as the 757, and the chief engineer of the new 757 program was Phil Condit, current chairman and chief executive officer of Boeing.
One of the key design goals of the 757 was commonality with the 767, a twin-aisle airplane developed in tandem with the 757. Boeing dropped the 757's T-tail in favor of a conventional tail and widened the nose, giving it a more blunt appearance than the original 727 nose and enabling engineers to fit the new high-technology 767 cockpit in the 757. The common cockpits allowed airlines to certify pilots simultaneously to fly both aircraft.
Boeing launched the 757 in the spring of 1979 with orders from Eastern Airlines and British Airways for 40 aircraft. Rolls Royce became a partner in the 757 when Boeing announced that it would use the Rolls Royce RB-211 engines on the 757.
On Jan. 13, 1982, only five months after the rollout of the 767, Boeing introduced the 757 to employees inside the assembly building at the Renton, Wash., site. Once again, Boeing did what many said no one could do: Boeing had developed two new commercial transports at the same time.
Source:In the early 1970s, Boeing began considering further developments of its narrow-body 727 trijet. The 727 was the best-selling commercial jet of the 1960s. Development studies focused around two tracks: a stretched 727-200 called the 727-300 and another study called the 7N7. The 727-300 would feature high-bypass engines in a trijet configuration while the 7N7 was a narrow-body twinjet which incorporated new materials and propulsion advances. There was initial strong interest in the 727-300, from airlines such as United and Braniff, but attention shifted to the 7N7. With the escalating fuel prices of the 1970s, airlines showed greater interest in a clean-sheet design with high-bypass-ratio turbofan engines, new flight deck technologies, lowered weight, improved aerodynamics, and reduced operating costs. These new technological leaps were also included in a parallel development effort, code-named 7X7, for a mid-size wide-body which would become the 767. By 1978, the 7N7 studies focused on two variants: a 7N7-100 with seating for 160, and a 7N7-200 with capacity for over 180 seats. The T-tail configuration of the 727 remained along with its narrow-body construction, forward fuselage, and flight deck layout, while a redesigned wing and new under-wing engines were added. Boeing touted the 7N7 as offering the lowest fuel burn per passenger-mile of any narrow-body airliner. On August 31, 1978, the 7N7 received its first airline commitments when Eastern Air Lines and British Airways announced launch orders totaling 40 aircraft for the âˆ’200 version. At this point, the T-tail was eliminated. These orders were formally signed in March 1979, at which time Boeing officially designated its new twinjet as the 757. The shorter âˆ’100 development, which failed to attract any orders, was dropped, with its role eventually taken by the versions of the 737. The 757 became very popular from its 1983 entry into service with Eastern and British Airways to the present day. Production of the 757 ended on October 28, 2004, after 1,050 had been built. The 757-200 is the most common variant, accounting for the majority of all 757s ordered. The 757-300 is the longest narrow-body twinjet ever produced. As of 2010, Delta Air Lines operates the largest 757 fleet, and 945 examples are in airline service worldwide Also of note, Boeing was experimenting with new house colors which eventually became the classic white fuselage with red and blue cheatlines of the 1980s and 1990s. Courtesy: Wikipedia