Boeing unveils 777X changes

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posted on Jun, 6 2014 @ 01:07 PM
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Some interesting changes have been made to the 777X design, after wind tunnel, and fluid dynamic testing revealed some minor issues with the current design.

The first change was an increase to the wingspan. The original design was 233' 6". That has been increased 2 feet, to 235' 6". It's using a wing design based on the 787-9, which is based on the changes made on the 7th 787-8 wing. The extra two feet will be added outside the folding mechanism on the wingtip, making each folding section 12 feet long.

The second change is to the flaps. It was found that the outboard flap was so long and thin that there was a risk of flutter. So to stiffen it, and reduce that risk, it is being cut into two shorter sections. That will give an outboard, intermediate, and inboard flap section, with an additional two hinges, and fairings added to each wing.

The third, and rather interesting change is to the engine cowling. The original design called for a chevroned edge to the aft engine fairing, similar to what's found on the 787 and 747-8. This reduced noise produced by the engine, but created some drag. Engineers have come up with a new way to do the same thing, without the chevrons or the drag. The change is made to the nozzle design. They've also investigating a CMC nozzle, which could tolerate higher temperatures out of the engine.

Thrust was increased on the engines, as a result of Emirates calling for an increase to deal with the temperatures they operate in, and it was recently revealed that to go with the increase (up to 105,000 lbs from 102,000), there was an increase in fan diameter from 132 inches, up to 133.5 inches.

777X changes




posted on Jun, 6 2014 @ 01:47 PM
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a reply to: Zaphod58

I wonder how much weight the add flap asm's and wing length will add to the aircraft.
Even though the new cowls are supposed to be lighter, I kind of liked the looks of the engine cowl chevrons.



posted on Jun, 6 2014 @ 02:01 PM
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a reply to: Sammamishman

I like that look too.

I would assume it doesn't add much, or they wouldn't have made such drastic changes. With it being a composite wing that should save them quite a bit of weight. Interesting that they're going with an aluminum wing box, and composite wing.
edit on 6/6/2014 by Zaphod58 because: (no reason given)





 
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