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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)



posted on Sep, 6 2018 @ 09:51 AM
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Boeing showed off WH001, the 777X static test airframe, on the assembly line. The aircraft is largely complete, and lacks a number of features that flying aircraft will feature, such as the folding wingtip. Next to WH001 is the aircraft that will be the first flying prototype.




posted on Sep, 6 2018 @ 12:41 PM
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Interesting to say the least.

There may be a slight increase in maintenance requirements with the new flap design and the benefit of the folding wingtip is that they don't have to worry about gate clearance fo adding the extra 2 feet wont change the parking dynamic much.

I also bet that alot of the weight of the new flaps will be offset by the reduced drag on the cowlings etc.



posted on Sep, 6 2018 @ 03:41 PM
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a reply to: FredT

Splitting the flap may reduce the load enough on the actuators that the same number can be used. This would result in no additional weight being added.



posted on Sep, 7 2018 @ 06:39 PM
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originally posted by: JIMC5499
a reply to: FredT

Splitting the flap may reduce the load enough on the actuators that the same number can be used. This would result in no additional weight being added.


I did not think about that part of it.



posted on Sep, 8 2018 @ 11:29 AM
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a reply to: FredT
I'm not familiar with the wing layout. If the actuators and hinges are in the right positions, just splitting the flap bondman might be all that is needed.



posted on Jun, 6 2019 @ 05:55 PM
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According to sources Boeing is aiming for June 26 for first flight. WH001 is doing systems integration testing and should begin taxi testing within the next two weeks.

The first flight and delivery schedule are at risk however, due to engine issues. An engine in pre- delivery testing had a health alert for a problem near the HPC. This area has had several issues during testing.



posted on Jun, 6 2019 @ 10:35 PM
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a reply to: Zaphod58

They had better not crap the bed on this one with the MAX debacle



posted on Jun, 6 2019 @ 10:59 PM
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a reply to: FredT

I'm more concerned with GE pulling a GTF debacle.



posted on Jun, 12 2019 @ 07:12 AM
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a reply to: Zaphod58
It would seem GE are upbeat about it staying on track. They appear to have a handle on some issues like a premature wearing of the VSV actuator arm. This sounds like shades of the CF-6, so I hope to god they have come up with a simplified design without all the annoying links and bearings buried under everything else.

I'm more interested personally in the wing fold mechanism and what design they will use, its reliability and its maintenance requirements.



posted on Jun, 17 2019 @ 09:08 AM
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GE is making changes to the second stage stator vane, which will be installed later this year. They're making the changes to 8 test engines, and 10 flight compliance issues. This is going to push first flight for the 777X into the October-November time frame.

aviationweek.com...



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