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Here's the 777X wing secret: It's just a longer 787 Dreamliner wing

The big technological breakthrough of the Boeing 777X wing is this: It will be very similar to the 787 Dreamliner wing, except a lot bigger.

“In general, the reason we have have so much confidence in the performance of wing is we’re using the same material systems as the 787 wing. We understand the 787 wing very well,” said Bob Feldmann, general manager of the 777X program, in a meeting with journalists on Tuesday.

“We’re evolving the architecture of the 787 wing to fit this bigger airplane,” he said.

The 234-foot wingspan of the 777X, so wide that the last 11 feet will have to fold on either side to fit the aircraft into the same airport gates, is part of what will make the aircraft more efficient. The longer and thinner wings, with what’s called higher aspect ratio, are more efficient to drive through the air than thicker, shorter aluminum wings the aircraft now uses.

Wind tunnel testing has shown that scaling up the 787 wing to fit the 777X is working, Feldmann said.

“What we learned is this wing loves to fly; it has given us very good slow speed performance. On high-speed cruise, learned the efficiency of the wing is what expected as well,” he said. “It is just a confirmation of the models that we used, which are mature models, because based on 787 wing.”

The most unusual part of the wing will be the outboard hinge, which is unusual enough that airlines rejected Boeing’s first proposals for it. Since then the company has been working to make it simpler, with proven technology.

The hinge, which will allow the outboard 11 feet of the wing to fold up on both sides, is intended to allow the 777X aircraft fit into the same airport gates as the current 777 models, which have much shorter wings.

“We are spending a lot of effort to make sure we have a a simple design,” he said, “to have a simple and very reliable mechanism, like a landing gear door."

http://www.bizjournals.com/seattle/news ... s+Journal)

Hinged wings, surely something I'd like to see malfunction while airborne.
Per

Nothing special here. Tails and rudders have been flapping on hinges since before you were born. As long as you don't fishtail them...

"You don't have to be unhinged to work at Boeing...."

Boeing is currently focusing on three strategic goals as follows (in order of importance):

1) Cost.
2) Cost.
3) Cost.

In order to meet these goals, the company has chosen to evolve current technology, rather than to implement new breakthrough technologies. Hope this helps.

Boeing begins 777x production
Article includes several images and a video of the first wing spar being transported within the plant and a hole being bored.

Excerpt:

Boeing's latest airliner has begun production ... untouched by human hands. Watched by an invited crowd at the Boeing production hangar in Everett, Washington, a one-armed robot on Monday started drilling into a 108-ft (33-m) long composite wing spar as the first step in assembling the long-range, wide-body 777X prototype. Billed as the largest and most efficient twin-engine jet in the world, it's scheduled to fly in 2019.

But what makes the 777X stand out is its lightweight wing design based on a composite spar made of over 400 miles (644 km) of carbon tape cured in a specially built autoclave. This results in 23 ft (7 m) more wingspan for a total of 235 ft (72 m). This allows the plane to maximize fuel efficiency in combination with its GE9X high-bypass turbofan aircraft engine, which punches around 100,000 lb of thrust and is ten percent more efficient than its predecessor.

It also means that the 777X has a distinct folding wingtip design to allow it to use standard airport gates. In addition, Boeing says that the 777X has larger windows that are easier to look out of, new lighting, and more interior carryon luggage storage.

https://newatlas.com/boeing-777x-robot- ... ion/51899/

...........windows that are easier to look out of.....

...........windows that are easier to look out of.....

Very much concur. I recently experienced tiny cheap composite crackerbox windows!

I also thought up a very mundane, but very real fear of the folding wings...

Failure of the retraction/extension mechanism and it's numerous safety sensors during ground operations, and subsequent painful delays.

...........windows that are easier to look out of.....

Is that a useful feature? From what people that fly more or less regularly tell me, 99% of the passengers fly with their window blinds closed and hosties close the remaining 1% every time they can (probably to stop people from seeing and filming pieces of wing coming loose, or engines exploding, or repeatedly turning on/off their reading lights, trying to call a hostie to report a flap misconfiguration... ).

The World's Largest Jet Engine Is Getting Ready to Fly (with photographs)

The GE9x will take to the skies on a Boeing 747-400 flying testbed later this year.

With a composite fan more than 11 feet in diameter tucked inside a 14-and-a-half foot nacelle, General Electric's GE9X is the biggest jet engine in the world. It will be used to power the new Boeing 777X long-range wide-body airliners currently under development. GE has been testing the GE9X around the clock and around the world as the the engine enters the final phases of FAA certification. Now GE is gearing up for the next step: flight.

A GE9X was recently mounted in the number 2 position on the left wing of GE's 747-400 flying testbed, as reported by Aviation Week. Although the GE9X will be used on twin-engine 777s, testing it on a four-engine 747 allows GE to evaluate the GE9X alongside established engines (CF6-80C2s) that have known performance envelopes and can serve as a control group of sorts.

GE released a photo of the GE9X mounted on the 747 (above). You can clearly see how the engine manufacturer had to shift the engine forward and up slightly above the wing's leading edge to provide enough ground clearance for the tremendous high-bypass turbofan. The GE9X is supported by a 19-foot custom strut adaptor to angle the engine up 5 degrees more than the three other engines on the flying testbed. Even then, there is only about a foot and a half of ground clearance below the hulking GE9X.

GE says ground clearance for the GE9X will be a concern mostly for ground operations rather than takeoff and landing. Just like with GE90 testing, used on previous versions of the 777, the fact that the aircraft's wings bow upward during landing is expected to give any aircraft with GE9X engines plenty of clearance to safely land. GE also removed six-foot wing extensions on the 747-400 to reduce the wingspan to a little over 195 feet, stiffening the wing to accommodate the weight of the large engine.

The engine mounted on the 747 flying testbed is the fourth of the program. GE plans to ship two engines to Boeing to be used on the first 777X next year, and Boeing hopes to flight test the 777-9, the first aircraft in the 777X program, in early 2019.

The initial GE9X, known as the first engine to test (FETT), was fired up for the first time in March 2016. That engine is now being used to prepare GE Aviation's ice testing facility in Winnipeg, Canada, for future GE9X testing. The second engine of the program is being prepared for the official FAA 150-hour block test slated for 2018, a robust performance test that will require GE to run the GE9X up to triple red-line conditions, meaning maximum fan speed, maximum core speed, and maximum exhaust temperature. A third engine is to undergo crosswind testing at GE's testing ground in Peebles, Ohio.

It won't be long now until the GE9X officially becomes the largest jet engine ever to fly.

Source: Aviation Week



http://www.popularmechanics.com/flight/ ... ight-test/

With a composite fan more than 11 feet in diameter tucked inside a 14-and-a-half foot nacelle...

Wow... I remember when engines came out that were so big a person could stand in the intake. Now there's almost room for two!

Here is takeoff of a 747 test aircraft with a new GE9X engine destined for the 777X.

As one commenter pointed out, "Good luck with crosswind landings." Another responded, “That’s the operator and mechanic’s problem.” 'Said every engineer ever.'

https://www.youtube.com/watch?v=UsY5g3i ... tion=share

You can't land a 747 at any appreciable roll angle anyway; the crosswind landing procedure is to land sideways and the gear's built to handle it. There's a thread about this here somewhere, unless it was on the old site...

PICTURES: Boeing reveals first assembled 777X ahead of static tests

Boeing has released its first images of a largely-assembled 777X and disclosed details about the structural testing its static test 777X will soon undergo.

The company posted video of its static test 777X and its first flight-test 777X on social media on 5 September.

Both aircraft are 777-9 variants and were at Boeing's Everett manufacturing site.

Boeing, which had previously released only digital renderings of the 777X, says the video follows the recent completion of the joining of the static test aircraft's body sections.

That test airframe will be the first 777X off the line at Boeing's Everett site, Doreen Bingo, Boeing's static test aircraft lead, says in the video.

The test airframe lacks engines and avionics systems and will be used exclusively for ground-based testing, she says.

Boeing will soon subject the airframe to a series of tests designed to evaluate the strength of structures like the wings, struts and the fuselage.

For instance, Boeing will "attach loads to the wing and distribute the load in a way that emulates air loads", she says. When subjected to this "ultimate load" test, the wing of the original 777 flexed 8.1m (26.5ft).

The static test aircraft's wing includes the wingtip but lacks the wingtip folding mechanism that will be found on production 777Xs, she says.
The static test is our opportunity to verify… all the load-bearing parts of the structure," says Bingo. "The intention is to test the structural strength of the airframe."

Boeing has not disclosed the timeline of its static test schedule.

The video also shows the first 777-9 flight test vehicle, which Boeing designates "WH001".

That aircraft will first fly in 2019, and Boeing plans to deliver its first 777-9 in 2020.

Boeing holds firm orders for 263 777X aircraft, according to FlightGlobal's Fleets Analyzer database

https://www.flightglobal.com/news/artic ... ad-451693/

At the same time another article shows to other test aircraft under production:
https://www.flightglobal.com/news/artic ... in-450065/

Hinged wings, surely something I'd like to see malfunction while airborne.
Per

It is designed to be perfectly flyable and controllable with asymmetric wing folding (for example, if one tip folds midair)

Hinged wings, surely something I'd like to see malfunction while airborne.
Per

It is designed to be perfectly flyable and controllable with asymmetric wing folding (for example, if one tip folds midair)

Quite the invention...

Winglets/sharklets are reckoned to economize 2-4% of fuel consumption, but the 777X's folding wingtips appear to lack them.
What's the deal?
Verbal?

Based on past Boeing parlour observations they simply add them later and then bigger ones and multiple ones.

May spread the work to keep Verbie’s family dry, clothed and fed?

A horizontal wiglet is more efficient than a vertical one.

Wiglets are used where you want to improve an existing "old" wing or when you want to keep the wingspan down to a max. Boeing found a different way to keep the wingspan down (on the ground) and have a wing as long as they wanted at the same time.

Sorry for the serious comment.

A horizontal wiglet is more efficient than a vertical one.

A distinguished aviation typist by the name of Garrison or something argued that orientation of the winglet doesn't actually matter, so long as its there.

Of course, his degree is not in any kind of engineering...

Sorry for the serious comment.

Seriousness is not exclusive from humour. Even Evan has his moments.

I thought winglets- to some extent- "dammed up" air that would otherwise spill over the side of the wing and generate wasted energy in vortexes.

I know that's a Kutta-free / non-phugoidal / non-Bernoulli ass-umption (not_unlike the nitrogen value of cow manure), but...

This may trigger a dissertation, but, oh well.

I thought winglets- to some extent- "dammed up" air that would otherwise spill over the side of the wing and generate wasted energy in vortexes.

That is actually a fairly correct description. The winglets try to be a barrier, but end up being an inconvenience, for the air in the high-pressure lower surface to go around the wing tip to the low-pressure upper surface zone. The winglet doesn't prevent the air from doing that, but it adds an obstacle that makes it more difficult and hence less air does it.

Now, did you realize that all your and my description works the same if the wiglet is horizontal? (which ends up being an increase of wingspan). Have you noted that the best gliders have very long span and no winglets? Have you ever heard how increasing the span reduces the induced drag? (although it is usually said of the aspect ratio). The winglets increase the length of the wing (even if fully vertical) if you measure it with a measuring tape from the tip, down the winglet, to the other end and up the winglet.

The difference is that the lift in the winglet points inward, cancelling each other, while in the increased span the lift point upwards (like, you know, lift) which has obvious advantages but one important downside: increased bending moment. When you have a wing already designed and tested to destruction and certified to withstand a certain bending moment, this can be a major inconvenience. Other downside is if you need to keep the length of the wing below a certain limit because it needs to fin in a parking zone of a specific size, especially if exceeding that side will make the airport send to you a 767-sized gate instead of a 737-sized one.

A horizontal wiglet is more efficient than a vertical one.

A distinguished aviation typist by the name of Garrison or something argued that orientation of the winglet doesn't actually matter, so long as its there.

Of course, his degree is not in any kind of engineering...

For the sake of reduction of induced drag, that's basically correct. But if you are designing a wing for a plane to have a given stall speed at max gross weight, then having it oriented horizontally will save you some wing+winglet area, which is less parasite drag and typically less material (although you will need a tougher spar)

I thought winglets- to some extent- "dammed up" air that would otherwise spill over the side of the wing and generate wasted energy in vortexes.

That is actually a fairly correct description....Now, did you realize that all your and my description works the same if the wiglet is horizontal?...

Yes, but there's still something mental about that 90-degree angle...thinking you are actually STOPPING the spill over.

I suppose if they were weightless and dragless you'd put huge ones on top AND bottom.

I thought winglets- to some extent- "dammed up" air that would otherwise spill over the side of the wing and generate wasted energy in vortexes.

That is actually a fairly correct description....Now, did you realize that all your and my description works the same if the wiglet is horizontal?...

Yes, but there's still something mental about that 90-degree angle...thinking you are actually STOPPING the spill over.

I suppose if they were weightless and dragless you'd put huge ones on top AND bottom.

Interesting comment.

2D airflow doesn't have induced drag. 2D airflow doesn't exist in practice, but it can be reproduced by putting an airfoil in a long wind tunnel with said airfoil spanning until both walls of the tunnel. In that condition, that would be equivalent to having infinitely large wingtip fences (which is the name of these special "winglets" you described above) the airflow behaves as 2D (there is no span-wise flow and the airflow profile in each section is the same), and there is no induced drag.

Do you know what other condition makes for 2D airflow and no induced drag? Infinite span.