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onewhippedpuppy 06-03-2017 07:06 AM

It takes a good chunk of airplane to carry 500k worth of payload, and you can't exactly hang that off of one wing. The twin fuse design gives you the space to package people and systems with a central position for that big mass of payload. The twin tails shouldn't be any more problematic than just having one. They are far enough apart I doubt you even get any airflow interference between them.

island911 06-03-2017 07:11 AM

yeah... I would have opted for a (huge) flying wing with underwing risers. (we have ridiculously fast control systems now)

island911 06-03-2017 07:16 AM

On the tails... my concern would be natural frequencies adversely loading the at the wing root. But I suspect they've added lots of extra CF.

Here's a fun fact... in testing, the B52 wings could be bent all the way up until touching tips... and still not break. (also would not return to normal (yielding) but still, not breaking, is impressive. )

stealthn 06-03-2017 07:44 AM

Sorry what's it for?

onewhippedpuppy 06-03-2017 10:14 AM

I'd like to see that. Most of the wing flex tests that I've seen are on the order of 45-60 degrees before something goes bang. Lots of good YouTube videos of more recent aircraft being tested.

Bob, it's to launch a reusable space vehicle into low earth orbit to launch satellites. It effectively replaces the stage one rocket phase of the launch sequence, at least in theory. The big advantage over a launch pad is that the Stratolaunch can reposition itself to launch the vehicle into other orbital inclinations and will be less limited by weather.

svandamme 06-03-2017 02:24 PM

I find it weird that they did not connect the rear horizontal stabilizers, as that would introduce more strength to the plane, making sure the 2 "booms' do not twist the main center section as much.

Like a P38

Bob Kontak 06-03-2017 02:34 PM

Quote:

Originally Posted by onewhippedpuppy (Post 9611801)
A friend of mine is one of their chief mechanical engineers. The scale of everything is massive, this is by many measures the largest airplane ever built.

Reminds me of a day when I was a yute. Airshow on the lake in Cleveland. B52 sitting there. I was amazed at the heft of the landing gear. Massive shocks. So many wheels.

Girlfriend says, Hey, Bob the sign says they can kill ya and it's ok. I had walked over the rope to get a closer look.

onewhippedpuppy 06-03-2017 03:04 PM

Quote:

Originally Posted by svandamme (Post 9612193)
I find it weird that they did not connect the rear horizontal stabilizers, as that would introduce more strength to the plane, making sure the 2 "booms' do not twist the main center section as much.

Like a P38

Considering they are going to hang and launch a space ship from the center wing, I would think there's probably all sorts of aerodynamic effects that could impact a central horizontal tail. Keeping them outboard is out of the wake of their payload.

RicN 06-03-2017 05:28 PM

https://uploads.tapatalk-cdn.com/201...2be6866aeb.jpg

pavulon 06-03-2017 05:40 PM

Quote:

Originally Posted by ckelly78z (Post 9610792)
So many questions, but the first....why two pilot stations/cabins ?

crew redundancy? I'm sure it has 2-3 of everything else.

island911 06-03-2017 08:24 PM

Looks like it's a longer wing span than the Spruce goose. (328ft)

http://4.bp.blogspot.com/-zJ2O-FpBAD...ine-colour.png

svandamme 06-04-2017 04:42 AM

Quote:

Originally Posted by onewhippedpuppy (Post 9612231)
Considering they are going to hang and launch a space ship from the center wing, I would think there's probably all sorts of aerodynamic effects that could impact a central horizontal tail. Keeping them outboard is out of the wake of their payload.

It's just a straight rocket innit.. In fact it actually looks a lot like a P38 with the rocket in position

2 nacelles
and a pod in the middle

http://aviationweek.com/site-files/a...tolaunch11.jpg

https://upload.wikimedia.org/wikiped...6px-P-38_2.jpg

So given the size of that thing.
Any turbulence that hits the left wing, will put load on the left nacelle..
But the right wing and nacelle might be doing something else.

To me it just seems logical to connect the nacelles in the back, to avoid to much twisting forces in the main front wing.

onewhippedpuppy 06-04-2017 07:33 AM

I totally understand the comments, you're making a C into a box and getting a lot more rigidity. I just think the engineers probably have a good reason to not connect the horizontals.

island911 06-04-2017 10:26 AM

Quote:

Originally Posted by afterburn 549 (Post 9612746)
Rutan has put a ship in space has he not?
I think critiquing him from the armchair is sort of absurd?
I would guess he has the empennage figured out?
Most of us can not make a decent paper aeroplane.

Yes, Rutan has put a ship in space, and some spectacular failure. The NTSB was critiquing him for that last design.

The Q is, who are you to be critiquing any who critiquing him? :cool:

Seriously, it is apparent that Rutan is an old-school aero-thinker (with lots of carbon fiber). He would never push forward any of the modern (computer controlled) configurations. It's not his thing. This project has much more in common with the spruce goose than say a B2. Add to that, Rutan like to poke at conventional configurations with quirky offerings. --it's his shtick.

red-beard 06-04-2017 04:18 PM

Quote:

Originally Posted by ckelly78z (Post 9610792)
So many questions, but the first....why two pilot stations/cabins ?

Pilots are only on one side. The other side is empty

dw1 06-04-2017 05:48 PM

I see the basic design approach as similar to the He-111Z glider towing aircraft of WW2, the Me-109Z experimental aircraft and the P-82 (later F-82) that saw service in Korea.

Notably, the He-111Z had 2 separate tail structures, although the Me-109Z and F-82 had a horizontal stabilizer that joined the two fuselages.

https://en.wikipedia.org/wiki/Heinkel_He_111#He_111Z

Interestingly, this design approach goes all the way back to 1915:
https://en.wikipedia.org/wiki/Blackburn_Twin_Blackburn

https://en.wikipedia.org/wiki/Messerschmitt_Bf_109_variants#Bf_109Z_.22Zwilling. 22

https://en.wikipedia.org/wiki/North_American_F-82_Twin_Mustang

island911 06-04-2017 10:40 PM

Quote:

Originally Posted by afterburn 549 (Post 9613172)
NASA has had some spectacular failures also.......
What was Rutan's?
I am not remembering.

https://upload.wikimedia.org/wikiped...Enterprise.jpg

https://en.wikipedia.org/wiki/SpaceShipTwo

Don't get me wrong, Rutan has done some cool things. Just don't go thinking he's infallible.

svandamme 06-05-2017 11:18 AM

Quote:

Originally Posted by tcar (Post 9545811)
Hopefully, Rutan and the SC engineers will read this thread and get right to work redesigning the plane.

The engineering prowess here is unrivaled. Good that all the shortcomings have been laid bare here.
:)

Wasn't aware that Rutan is so holy that we can't even discuss the design.
What's your fanclub membership card number???


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