Aircraft will initially provide baseline wing load data to aid new airliner's design

Boeing has decided to use a leased 747-400 to prepare the ground for the forthcoming 747-8 stretch in a similar way that it is using a 777 for concept validation and risk-reduction on the 787.

The aircraft, a leased ex-Malaysia Airlines 747-400 Combi owned by Guggenheim Aviation Partners, is initially being rigged with sensors to provide baseline wing load data to assist with finalising the design of the all-new, 68.5m (225ft)-span super-critical wing section, which is much thicker than the current 1960s-era configuration.

The start of the initial test period, planned to last about three weeks, is believed to have been delayed while Boeing waits for the US Federal Aviation Administration to grant it an experimental certificate for the testbed.

Further tests beyond the current loading scope are considered likely, given planned -8 design features such as a trailing-edge wedge, partial fly-by-wire flight/spoiler controls, drooped ailerons and manoeuvre/gust-load alleviation, but Boeing declines to comment.

The cost of the 747 testbed is expected to be reflected in increased 747-8 research and development expenses forecast for the rest of 2006. But Boeing says: "The R&D spending is a result of continued discussions with our customers on both the Freighter and Intercontinental versions.

"Based on those discussions, we have further improved the wing design and airplane configuration to provide more robust performance, lower noise, increased fuel efficiency, and a better passenger experience."

Boeing opened and closed the swing tail of the 747-400 Large Cargo Freighter for the first time in mid-October. The 747LCF - which will be used to transport major components of the 787 Dreamliner - is undergoing tests at the manufacturer's Everett factory. 

 747 -lcf tail
© Boeing


Read Flight International deputy editor Andrew Doyle's News Blog on the 747-8 testbed and why Boeing has to lease aircraft to flight test while Airbus retains its own fleet 

Source: Flight International