Guy Norris/LOS ANGELES
Boeing is claiming that its new stretched 747-400X design is capable of meeting and even beating the direct operating costs of the all-new Airbus A3XX.
The startling assertion is based on revised performance estimates for the 747-400X, plus new, independent airline analysis of the latest A3XX proposals. "We are refining the configuration and we are closing in [on Airbus]," says Commercial Airplanes Group product development director, David Anderson. "We don't just equal it, we are better than the A3XX."
Boeing believes the direct operating costs of 747-400X versions could be 7-8% better than those of the baseline -400. Airbus has set itself the target of achieving a 20% improvement over the -400 with the A3XX. Part of Boeing's optimism is based on new data showing "a more accurate seat count comparison between the A3XX and -400. We have independent validation from an airline that was on the A3XX team," says Anderson.
The claim comes as Boeing prepares to make final refinements to its proposed 747-400X family, the largest of which is a 500-plus passenger stretched version with a range of 14,330km (7,745nm). A final series of windtunnel tests of the definitive configuration are planned in the second quarter of next year at Farnborough in the UK. "We are pretty solid on what it will look like," says Anderson. "We are not at the authority-to-offer stage yet, but we have been to the board of directors to keep them informed." Service entry is expected no earlier than 2003/04.
To improve range and capacity, Boeing has increased the wing root insert and is studying a blended winglet design as well as raked tips. The proposed insert is now as much as 2.67m (9ft) at the wing root, increasing the total span by around 5.33m. The span would grow from 64.5m on the current -400 to around 69.8m on the new version, and would sport the trailing edge wedge aerodynamic modification along the entire span.
The baseline 430-seat -400X passenger model would be fitted with the revised wing and larger wing box which boosts capacity by around 30 passengers. The 500-seat -400X Stretch version would incorporate a further 9.7m fuselage stretch. Range of the two models is put at 16,100km and 14,430km, respectively. Together with re-lofting of the inboard wing section, the larger root insert would provide much more fuel volume in a thicker section, adding more than 800km in range with 500 passengers. Freight and combi versions of the -400X are being studied and "the freighter version looks really attractive", adds Anderson.
Source: Flight International
