GUY NORRIS / LOS ANGELES
Boeing plans to canvas airlines this month on proposed changes to the "Quiet" 747-400X derivative designed to keep the aircraft competitive for 10-15 more years.
New details of the studies, first revealed last month, cover Boeing's outline 747 development plan for 2003 to 2004 (Flight International, 1-7 January).
These major new derivatives will build directly on the higher weight -400ER, which is set to make its first flight in early July, and be delivered to launch customer Qantas in October.
The development study, believed to be known internally as the 747-400QLR (Quiet, Longer Range), is aimed primarily at meeting stringent QC2 noise requirements set by London Heathrow and maintaining the 747's competitiveness.
Although Boeing remains vague on "QLR" details, they are thought to include a proposed maximum take-off weight of 417,700kg (920,000lb), added fuel capacity through several options including a wider-span horizontal stabiliser, aerodynamic changes to reduce airframe noise, engine nacelle changes and raked wingtips. Deliveries could begin late next year.
Boeing says, based on airline response, a decision on the direction of the product line could be made around mid-year. This would provide the possible basis for at least two more phases of 747-400X family growth between now and the end of the decade.
The first of these, covering 2004-7, is likely to include more extensive use of overhead space in the aft fuselage, as well as "value-added" avionics, improvements in dispatch reliability towards 777-like levels and a reduction in maintenance costs.
A longer term phase, from 2008, would see the continuing long-range development of the 747, as well as renewed focus on the performance of the freighter version.
Brand manager for the 747 William Droppelman says plans for the next phase of 747 development will firm up "once we get verification from our customers that we are doing the right things".
Proposed engines for the new models are primarily the General Electric CF6-80C2B5F and Pratt & Whitney's PW4062. The increased weights of the new aircraft effectively rule out the Rolls-Royce RB211-524GT/HT engine, adds Boeing.
Source: Flight International
