Boeing 787 Dreamliner - Mark Wagner [21]
The big decision hinged on whether the 7E7 should have a seven- or eight-abreast economy cabin, the smaller option representing a cross section similar to that of the 767. The larger fuselage cross section, though narrower than the nine/ten-abreast seating width of the 777, would still be wider than the competing A330/340 family. Both designs could accommodate LD3 containers in the cargo hold but would be held within the contours of a double-lobe or “double-bubble” fuselage rather than the structurally efficient circular design adopted for the first time with the 777.
“Boeing has always done double-bubble fuselages, although the 777 was circular and the reason for that was the move to the nine-abreast configuration. However, we got criticized by some because of the space that created above the ceiling, so all of the Yellowstone studies were double-bubble,” said Roundhill. Boeing later devised innovative upper-lobe crew rest areas for the 777, which came into their own for the 777-200LR/300ER models, but the lower-capacity targets of Yellowstone and 7E7 also played in favor of the slimmer cross section and the double-lobe approach.
By February 2003 the airlines were being briefed on further refined offerings, dubbed the 7E7-300X
and 7E7-400X. The 300X seated 228 passengers in a three-class arrangement and offered a design range of 7,800 nautical miles, while the stretched 400X seated 268 and could fly about 7,000 nautical miles. Crucial performance targets included more range and 23 percent better fuel burn per passenger than the A330-200, as well as cruise speeds as high as Mach 0.89—somewhat faster than those being publicly discussed just a month of so earlier.
At the end of the following month, on March 28, Boeing filed for new type and production certificates for the 7E7 with both the FAA and the European JAA. “That’s a major milestone in the program,” said newly appointed 7E7 Vice President Mike Bair. “That starts the process for the production plan of the aircraft and is a milestone we didn’t pass through on other recent derivatives.” In other words, the 7E7 was the first new Boeing model since the 777 to get this far, and events augured well for a positive “authority to offer” decision from the Boeing board, expected in December 2003.
With the 7E7, Boeing wanted to ride the wave it had begun with the Sonic Cruiser. However, the first visual impressions were significantly different from the baseline reference concept (see inset) unveiled by Walt Gillette to a gathering at the Society of Automotive and Aerospace Engineers conference, held in November 2002 at the Sheraton Crescent Hotel in Phoenix, Arizona. Inset courtesy Lia Ravelo
Before then, however, Boeing faced a hectic year. “Most of 2003 will be spent defining what it will look like, and convincing ourselves we have a viable business case,” said Bair.
The crucial cross-section decision was also revealed in late March, the company opting for the wider eight-abreast cabin with a roughly 226-inch diameter. This made it about 28 inches wider than the 767 and l8 inches narrower than the 777, while giving it the advantage of at least few inches extra width over the A330.
Wingspan differences between the 7E7 family members was “one of the biggest complications,” said Mike Bair. The conundrum was finally solved by fitting raked tips to the 197-foot span of the longer-range model (originally about 188 feet), and blended winglets to the 170-foot-span, gate-size-restricted short/medium-range version. The raked tips also were chosen for the stretched, longer-range model, which also was given extra wing area for a total wingspan of almost 208 feet. The elegant curve of the Korean Air–built raked tip is well illustrated on this image of ZA001. Mark Wagner
Like first-time parents dithering over names for their unborn child, Boeing once again changed the 7E7 designations. The 7E7-300X/400X disappeared, to be replaced for a short time by the 7E7 and 7E7STR (stretch). Within weeks, however, these morphed once more into two main subsets, the baseline