Boeing to Unveil the New 747-400X,
It'll Fly Farther and Will be Quieter

Almost exactly a year after canceling the stretched 747X, Boeing will announce today that it's developing another new version of the long-running widebody, the 747-400X. Boeing firmly declined requests for advance interviews on the improved aircraft, but models on the stand show a 747-400X passenger aircraft and companion 747-400XF freighter.

Designed as a longer-range, quieter aircraft than the current top of the line, the new 747-400ER, the 747-400X will be the first major new derivative of Boeing's biggest aircraft since the 747-400 itself was launched in the mid-1980s. Gone are the 747-400's trademark winglets, replaced by the raked tips also used on the extended-range 777 and 767-400ER. The raked tips extend the wingspan, reducing drag. But they don't add as much area as a simple span increase, so they impose less load on the wing structure and the wing is lighter.

Also new are the "chevron" engine nacelles, with serrated edges on the core and fan nozzles. The chevron nozzles promote mixing of the bypass and core flows and the mixing of the bypass flow with the ambient air, and reduce jet noise.

Details of the timing, market and performance of the new 747 are to be revealed today. Boeing denies that the new aircraft is being offered because of slow 747 sales since the launch of the Airbus A380, or in response to Airbus' decision, in late 2000, to develop the A380 to meet London Heathrow's QC2 noise standards. "The aircraft are in two different markets," Boeing says.

Boeing has just started major assembly of the first 747-400ER, destined for launch customer Qantas. With a maximum takeoff weight of 910,000 pounds, 35,000 pounds more than the in-service aircraft, and underfloor auxiliary fuel tanks, the ­400ER offers 435 nautical miles more range, enough to fly from Los Angeles to Melbourne. The first of six aircraft for Qantas will be delivered in October.

By Bill Sweetman