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-   -   Boeing Transonic Truss Braced Wing Concept (https://www.pprune.org/rumours-news/617051-boeing-transonic-truss-braced-wing-concept.html)

Lyneham Lad 9th Jan 2019 10:57

A little more information here on Aviation Week.

Less Hair 9th Jan 2019 11:18

Why "transonic" at Mach 0.8?

Intrance 9th Jan 2019 11:44

LMGTFY

Google should show you a nice result from Wikipedia explaining “why transonic at M.80”.

DirtyProp 9th Jan 2019 12:19

If it's really as efficient as they claim it to be why not? Sure it looks a bit funny, but who cares?

Hopefully Easa in its infinite wisdom won't come up with a different rating....:E

KiloB 9th Jan 2019 16:04


Originally Posted by Intrance (Post 10355966)
LMGTFY

Google should show you a nice result from Wikipedia explaining “why transonic at M.80”.

Even though I sat at the back, I did listen in (some) lectures, so I understand the ‘Critical Mach Number’bit. What I don’t understand is how this super duper new design hits Critical Mach at a SLOWER speed than thousands of existing airliners?

CRayner 9th Jan 2019 18:27


Originally Posted by Pilot DAR (Post 10355558)
Is different from:



I think that the "pitch" is European, (and perhaps metric?), where the "field" is American (funny shaped ball & amoured players), and I presume imperial. I'll try to find the conversion to cubits to help everyone out ;)


Both originally described in Imperial units (yards). Metric equivalents are given, and broadly similar lengths, about 110m or between 110 and 130 yards. Individual pitches vary quite a bit, so it is not a great unit for use in aeronautical engineering where I understand precision is generally preferred. So about 150ft span. Give or take. A bit.

er340790 9th Jan 2019 18:35


Tail from a 146. Fuselage and undercarriage from an ATR72 and a stretched strutted wing from a Shorts 360.
:D :D :D I thought it looked vaguely familiar. :ok:

Just don't try flying one into Known Icing Conditions!!! :eek:

PAXboy 9th Jan 2019 19:09

From the Reuters report:

Boeing said the jet ideally would reduce fuel burn by 60 percent compared to an aircraft in 2005, but said it did not have final data to compare the fuel savings to present-day aircraft.
Oh yes they do have the numbers!!! It's just that '60%' sounds better than 10/15% or whatever it might be. That aside, it appears to be progress (state sponsored as mentioned) but then states all around the world always have.

FlyXLsa 9th Jan 2019 19:54

China recently flew a 1/10th scale similar plane.
https://cimg4.ibsrv.net/gimg/pprune....05a508e6b.jpeg

Mechta 9th Jan 2019 21:05


Originally Posted by KiloB (Post 10356172)


Even though I sat at the back, I did listen in (some) lectures, so I understand the ‘Critical Mach Number’bit. What I don’t understand is how this super duper new design hits Critical Mach at a SLOWER speed than thousands of existing airliners?

As Boeing's proposal has a very narrow chord and only a small amount of sweep, the thickness to chord ratio may well be higher than current airliners, so the pressure drop on the upper surface will be high and the lower critical mach number lower than current designs.

Airbus gave a presentation to employees back around 2005, at which they showed proposals for A320 series replacements. They stressed that low cost airlines are interested in the maximum flights per day, not maximum speed, and that bigger time savings can be achieved by avoiding reliance on jet bridges and airport supplied steps, hence the aircraft should be low to the ground and carry its own steps. Potentially the cabin crew could unload any hold baggage for passengers to carry, avoiding the need for baggage handlers too. The Airbus design looked a bit like an Ilyushin 76 but with rear fuselage-mounted engines (as per DC-9 etc.) Presumably Boeing are getting the same message from their Lo-Co customers.

By the way, what is wrong with calling a strut a strut? Are struts only found on Cessnas and old aeroplanes?

Sorry Dog 10th Jan 2019 00:25


Originally Posted by Alpine Flyer (Post 10355391)
Looks like a mix between an Avro, a 737 and a 172.

I was going to say part 757 mixed with part Romulan Bird of Prey... minus the disrupter of course.

https://cimg4.ibsrv.net/gimg/pprune....333ee8081a.jpg

WillFlyForCheese 10th Jan 2019 00:37


Originally Posted by Sorry Dog (Post 10356588)
I was going to say part 757 mixed with part Romulan Bird of Prey... minus the disrupter of course.

That is clearly a Romulan D'deridex class warship. Not even close to a bird of prey . . .

Sorry Dog 10th Jan 2019 00:53


Originally Posted by Mechta (Post 10356474)
As Boeing's proposal has a very narrow chord and only a small amount of sweep, the thickness to chord ratio may well be higher than current airliners, so the pressure drop on the upper surface will be high and the lower critical mach number lower than current designs.
.

I wouldn't doubt that ratio is actually lower than current even with a small sweep. Look at planes like the F104 whose wing had excellent supersonic drag despite having little sweep... wonder if Mr. B will include protective covers for the sharp leading edge like Lockheed did.


Originally Posted by Mechta (Post 10356474)

Airbus gave a presentation to employees back around 2005, at which they showed proposals for A320 series replacements. They stressed that low cost airlines are interested in the maximum flights per day, not maximum speed, and that bigger time savings can be achieved by avoiding reliance on jet bridges and airport supplied steps, hence the aircraft should be lo,w to the ground and carry its own steps. Potentially the cabin crew could unload any hold baggage for passengers to carry, avoiding the need for baggage handlers too.

Cabin crew will be too busy cleaning up cabin. The pilots will likely be asked to perform this essential duty... especially since things like fuel lift, weight and balance, and preflight checklist will be automated in the new 787 DUM (Dreamliner Ultra Max), so airline management will want the pilots to stay as efficient as possible.

Sorry Dog 10th Jan 2019 00:56


Originally Posted by WillFlyForCheese (Post 10356590)
That is clearly a Romulan D'deridex class warship. Not even close to a bird of prey . . .

somehow I knew that I would screw up the Trekkie lore. https://cimg0.ibsrv.net/gimg/pprune....42a4d4e569.jpg

737er 10th Jan 2019 00:57

The best news is the sonic boom it creates is completely silent. The struteirons will increase roll rate. Game Changer!

New buzzword for 707 speed: Transonic!

RatherBeFlying 10th Jan 2019 01:36

Looks like Dr. Seuss designed another creature:p

MarkerInbound 10th Jan 2019 01:43


Originally Posted by Peter G-W (Post 10355394)
“Over half the length of a football pitch”: how many double decker buses is that?

It comes out to just under 30 and a half smoots.

Mechta 10th Jan 2019 10:33


Originally Posted by Sorry Dog (Post 10356604)
I wouldn't doubt that ratio is actually lower than current even with a small sweep. Look at planes like the F104 whose wing had excellent supersonic drag despite having little sweep... wonder if Mr. B will include protective covers for the sharp leading edge like Lockheed did.



Cabin crew will be too busy cleaning up cabin. The pilots will likely be asked to perform this essential duty... especially since things like fuel lift, weight and balance, and preflight checklist will be automated in the new 787 DUM (Dreamliner Ultra Max), so airline management will want the pilots to stay as efficient as possible.

No, they wouldn't want pilots wandering around outside the aeroplane. They might see a hydraulic leak or something, which would incur local maintenance costs and schedule delays.

horizon flyer 10th Jan 2019 12:13


Originally Posted by Sorry Dog (Post 10356604)
I wouldn't doubt that ratio is actually lower than current even with a small sweep. Look at planes like the F104 whose wing had excellent supersonic drag despite having little sweep... wonder if Mr. B will include protective covers for the sharp leading edge like Lockheed did.



Cabin crew will be too busy cleaning up cabin. The pilots will likely be asked to perform this essential duty... especially since things like fuel lift, weight and balance, and preflight checklist will be automated in the new 787 DUM (Dreamliner Ultra Max), so airline management will want the pilots to stay as efficient as possible.

Once supersonic a straight wing is OK as long as the wing tips are inside the shock wave from the nose. Sweep is only needed to fly subsonic closer to the speed of sound. The first design for a super sonic aircraft, the Miles M52 had a straight wing with triangle shaped wing tips and a flattened smoothed diamond aerofoil called biconvex When the Bell team visited Miles Aircraft ltd in the fall of 1943 they where shown the finished design and idea of putting a rocket engine in it and dropping it out of a Lancaster. The Bell team, who had no idea how to design a super sonic aircraft at the time copied the design but with the rocket engine but used a subsonic aerofoil on the Bell X1 and normal wing tips.

megan 10th Jan 2019 23:48


The Bell team, who had no idea how to design a super sonic aircraft at the time copied the design
The Bell team did not copy the design. You've been listening, it seems, to the garbage sprouted by Eric "Winkle"Brown. The Bell aircraft owed absolutely nothing to the M.52. In fact the American who was briefed on the M.52 commented that the Miles had some interesting innovations, such as biconvex section and one piece tailplane, but had nothing of real interest to offer and little need to follow its progress.


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