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Rutan Ski-gull

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rv6ejguy

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The Ski-Gull is not really typical of your average light aircraft- folding, higher aspect ratio wing and a very large fuel fraction compared to most. Rutan has a lot of real world experience with these design compromises on his two round the world designs and he's stated this aircraft must be robust to take a bit of pounding. Probably has his reasons for struts.
 

jetblackaircraft

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Norman, OK
The Ski-Gull is not really typical of your average light aircraft- folding, higher aspect ratio wing and a very large fuel fraction compared to most. Rutan has a lot of real world experience with these design compromises on his two round the world designs and he's stated this aircraft must be robust to take a bit of pounding. Probably has his reasons for struts.
It looks to me from the photos that the reason for the struts is that his wing is super high above the cabin to get it away from the water and clear the propeller. If he didn't have a strutted wing he'd be looking at a seriously heavy pylon to attach the fuselage to the wing. Look at the front view, it's a really thin structure as it is. If he didn't have support from the struts he'd have a massive, beefy structure that would add weight and unless he tried to keep it thin, also drag.
 

autoreply

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Pylon loads (unstrutted) are tiny; simply do the math yourself or look at the attachment points of a sailplane and compare to the spar.
Pylon can be much thinner as the main spar. With high AR and high wing mass, yaw loads are the biggest issue. Struts don't do anything there...
 

KevinThorp

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Charleston, SC
I notice the wing tips are swept, I would have expected epileptic wings for nest L/D and ratio, sort of like the Spitfires, but stretched. That is what I have seen on most of the gliders I have been around.

Is this a design element of being a MOTORglider vs a straight glider?
Rutan likes to hot-wire wing cores from foam blocks. You fasten airfoil profiles to both ends and "trace" around them with the hot wire. Using this method you can create straight or tapered wings, but not elliptical. A 2 part straight/tapered wing approximates an ellipse, but is much simpler to construct.

Years ago I was disappointed to hear Burt had given up designing small aircraft for the GA market. This new plane is pretty exciting. Can't wait to see it fly.
 

CutieDarkFae

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The mystical land of OZ
Rutan likes to hot-wire wing cores from foam blocks. You fasten airfoil profiles to both ends and "trace" around them with the hot wire. Using this method you can create straight or tapered wings, but not elliptical. A 2 part straight/tapered wing approximates an ellipse, but is much simpler to construct.

Years ago I was disappointed to hear Burt had given up designing small aircraft for the GA market. This new plane is pretty exciting. Can't wait to see it fly.
CNC machines are getting cheaper and more available every year. You can get your cores CNC'd now easily, so I don't see how ellipses aren't possible with modern tech.

I agree that the plane is exciting, but I can wait to see it fly, I have no choice :(
 

Jay Kempf

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CNC machines are getting cheaper and more available every year. You can get your cores CNC'd now easily, so I don't see how ellipses aren't possible with modern tech.

I agree that the plane is exciting, but I can wait to see it fly, I have no choice :(
The gain in efficiency between a triple taper wing and an elliptical wing is not even measurable in the real world. Double tapers can be close to optimal structurally and aerodynamically and that with a large portion of the span with no taper at all.
 

Riggerrob

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Those swept wing tips are the current fashion for Formula One and Sportsman class racers at the Reno Air Racers. We have also seen similar swept wing tips on recently-desigend competition sailplanes. Scaled Composites has long had the tools to cut elliptical wings since they have been using CNC cutters since at least 1993.
 

Topaz

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Thanks very much for posting that. Interesting news. One of the things I like about Rutan is that he doesn't expect perfection on the first go, and is open to making changes based on actual tests. Not as risk-averse as we, as a society, seem to have become in general.
 

Kingfisher

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Perth, WA, Australia
View attachment 41806



link to my vsp model
VSP Hangar | MH6
Its ok i wont charge Burt a licensing fee;). ps i charge a fraction of what burt does for conceptual design !:) :lick:
I agree, yours is quite similar. I was also reminded of the Centaur/Gull aircraft, except these guys have been tinkering around with the concept for a long time, while Rutan got his off the ground already.
17700.gif.jpeg
 

Victor Bravo

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KWHP, Los Angeles CA, USA
What strikes me about the photos of the pilot sitting in the cockpit, and the group photo of everyone standing in front of it.... is how small the airplane is. I had wrapped my head around the idea that it was a larger aircraft. Looks like the cockpit is about the size of a Long-EZ.

It sure looks cool.
 
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