Flying wing as cheap and simple option for basic fun flying.

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

jedi

Well-Known Member
Joined
Aug 8, 2009
Messages
3,500
Location
Sahuarita Arizona, Renton Washington, USA
Only from the outside. It's still a tube aluminum or carbon fiber for the basic frame. 2 leading edge tubes, 1 keel, and over the decades from 1 cross spar, to a 2 piece hinged floating cross spar.

The "control bar" and kingpost, are cable braced Structure that takes the lift & landing loads.

Competition gliders eliminate the kingpost & it's wires, with a heavier and more complex cross spar, internally. Northwing also makes strut braced trike wings and a glider, that eliminate upper rigging, and the main side cables, at the cost of weight.

The basic frame is indeed simple. A time traveller bringing the bare frame of a modern recreational glider would impress a 1979 glider maker with the high aspect ratio, and the hinged cross spar might inspire an early revolution in control/handling, but without the 3 dimensional sculpture that is the sail & battens, would not shock anyone.

Ironically, the complex sail alone would be a failure, if it was teleported to a 1979 glider builder, unless he saw the articulated frame too. It literally would be nigh impossible to turn.

In contrast, for a Kasper Wing, or Quicksilver, is very easy to grasp the ladder frame and cable bracing. The part count is higher, than a flex wing, but only for the hard metal or composite parts. It's still going to be one wing skin/sail. The complexity & curves of that sewn "part" are orders of magnitude different.

The platform of post # 2415 is intended to be a folding flex wing a bit more complex than the modern hang glider.

The comparison with the rigid ladder wing of the Kasperwing is valid as far as the simple and cheep goes except the Kasperwing does not pack into the “tube” of a hang glider for storage and transport.

The hang glider is no longer simple and cheep when the storage and transport of the flex wing is required and the wing morphs into the rigid wing of a Swift or an Atos. (Billy time for you to comment here).

VB - The goal is to apply the platform of post # 2415 to a flexwing folding frame that does not need the complex controls of the rigid flying wings whether it be a Blackstrom plank or a B-2 stealth bomber.
 

jedi

Well-Known Member
Joined
Aug 8, 2009
Messages
3,500
Location
Sahuarita Arizona, Renton Washington, USA
Jonathon, is that you?
Yes master. Is that you?

As you can see, I have been keeping the faith and awaiting your call.

What shall I do now fly higher and faster or lower and slower maneuvering around objects and thru the forest and diving deep under water into the sea?

I would like to just once land on a wire. I have mastered landing on a post as you suggested. The takeoff was even easier than the landing. It was so cool. This was before I mastered the task. I do know better photos exist but not all are easy to find or posted in the internet because the elders are still complaining.

1661211128268.jpeg
 
Last edited:

addaon

Well-Known Member
Supporting Member
Joined
Feb 24, 2008
Messages
2,342
Location
Kanab, UT
Yeah, but remember when practicing the spot landings and you porpoised a bit too aggressively and that darn cone went right where it shouldn't?

I've landed on top of a wire (barbed wire fence) once, posed, and coolly stepped off... only to go into "oh crap zero wind charge forward keep kiting" to avoid putting the wing down on... the barbed wire fence.
 

Tiger Tim

Well-Known Member
Joined
Apr 26, 2013
Messages
5,085
Location
Thunder Bay
I still do not have a translation for BDSM lift curves but realize perhaps it is best to not know.
I saw that creep in earlier and had a chuckle. I assume someone meant to say BSLD but got mixed up.

BSLD being Bell-Shaped Lift Distribution which often comes up in flying wing discussions. I think the Horten brothers were big on it.
 

jedi

Well-Known Member
Joined
Aug 8, 2009
Messages
3,500
Location
Sahuarita Arizona, Renton Washington, USA
I saw that creep in earlier and had a chuckle. I assume someone meant to say BSLD but got mixed up.

BSLD being Bell-Shaped Lift Distribution which often comes up in flying wing discussions. I think the Horten brothers were big on it.
That is kind of what I thought but was not mentioned till now. The next question, which should not be answered here, is how did it slip in and why was it not clarified before now?

[More chuckles!]
 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
3,358
Location
Rochester, NY, USA
I assume someone meant to say BSLD but got mixed up.
Nope. Deliberate joke. Acronym overload editorial, if you like. :)
Post #2412.
Then a harness reference. ;)

Sure, if you Want to come up with alternative words to match that acronym, feel free!
Board Design System Management is fairly close as it submits to a group in a different context.
 

Aesquire

Well-Known Member
Joined
Jul 28, 2014
Messages
3,358
Location
Rochester, NY, USA
Re: over wing struts.

Personally not my favorite.
It's been done well, see VP-1 & VP-2 post above. PA-25 Pawnee, too.
The negatives include drag in the higher speed flow over the wing, ( vs. Under wing struts ) and that the struts are in compression, so need to be stronger than struts mostly in tension in flight.

But if you want a low wing and low weight, over wing struts are workable. If low drag is important, not the best choice.

I also have a rant on landing gear mounted bracing like on the Mini-MAX, or Airdrome Dream. Not relevant here. :)
 

Victor Bravo

Well-Known Member
Supporting Member
Joined
Jul 30, 2014
Messages
11,410
Location
KWHP, Los Angeles CA, USA
There are several pepole here on HBA who have the engineering training to say I'm wrong, but... if you took the weight of the struts (fifteen or twenty or even thirty pounds) and correctly added that much weight to the spars, I beieve that (in the size and thickness range of most E-AB wings) you would wind up with an equally strong cantilever wing... with lower parts count, less to build, less drag, and likely less cost.

Very thin wings will benefit less from this, and thick wings would benefit more.

A kingpost and cable bracing will weigh a lot less, but I am limiting this comparison as being between a cantilever wing and steel or aluminum tube struts.

You will have a hard time convincing me that a strut braced Debreyer Pelican will have any advantage over a cantilever Pelican.
 

cluttonfred

Well-Known Member
Supporting Member
Joined
Feb 13, 2010
Messages
9,732
Location
World traveler
Re: over wing struts.

Personally not my favorite.
It's been done well, see VP-1 & VP-2 post above. PA-25 Pawnee, too.
The negatives include drag in the higher speed flow over the wing, ( vs. Under wing struts ) and that the struts are in compression, so need to be stronger than struts mostly in tension in flight.

But if you want a low wing and low weight, over wing struts are workable. If low drag is important, not the best choice.

I also have a rant on landing gear mounted bracing like on the Mini-MAX, or Airdrome Dream. Not relevant here. :)

1661446778679.png

There is also the CallAir cabin model in many iterations depending on the engine. Aesquire makes a great point that people often point out that struts are stronger in tension than compression so struts above the wing are heavier, but they forget that struts above the wing still make a lighter low wing than a cantilever design. Plus I am pretty sure that "drag at higher speeds" has never been an issue in any Volksplane. ;-)

 

rotax618

Well-Known Member
Joined
Oct 31, 2005
Messages
1,663
Location
Evans Head Australia
Consider Euler’s formula for non-concentric slender struts, a jury strut at the centre increases the buckling resistance by the square of the length.
10C8A480-8A55-4A1A-BA8A-3BB74E4AC34B.jpeg
 

MR101005

Well-Known Member
Supporting Member
Joined
Mar 21, 2019
Messages
59
There are several pepole here on HBA who have the engineering training to say I'm wrong, but... if you took the weight of the struts (fifteen or twenty or even thirty pounds) and correctly added that much weight to the spars, I beieve that (in the size and thickness range of most E-AB wings) you would wind up with an equally strong cantilever wing... with lower parts count, less to build, less drag, and likely less cost.

Very thin wings will benefit less from this, and thick wings would benefit more.

A kingpost and cable bracing will weigh a lot less, but I am limiting this comparison as being between a cantilever wing and steel or aluminum tube struts.

You will have a hard time convincing me that a strut braced Debreyer Pelican will have any advantage over a cantilever Pelican.

In a small low-wing aircraft with a cantilever wing, the main spar usually goes right through the cockpit on the fuselage floor. That's why - depending on the height of the spar - important space for the pilot is lost. In the worst case the fuselage becomes higher than necessary to guarantee the pilot's mobility and the CG on the right place.

I don't know. But perhaps Evans avoided these problems by placing the struts on the top of the wings, allowing his low-wing aircraft to eliminate the spar portion in the cockpit.

Visually, this arrangement is certainly unusual. But if it serves the purpose, why not?
 

Victor Bravo

Well-Known Member
Supporting Member
Joined
Jul 30, 2014
Messages
11,410
Location
KWHP, Los Angeles CA, USA
I was speaking primarily of the Dereyer Pelican, which is mid-wing, and the main spar forms the pilot's seat backrest. The wing section is thick, allowing for a deep spar.

I completely stand by my assertion that on a small, cheap, smple flying wing (the Pelican, the Backstrom Plank, the Facet Opal) you will not see a useful benefit from a strut braced wing as shown on the A-12 Bagoas posted above.
 

cluttonfred

Well-Known Member
Supporting Member
Joined
Feb 13, 2010
Messages
9,732
Location
World traveler
I was speaking primarily of the Dereyer Pelican, which is mid-wing, and the main spar forms the pilot's seat backrest. The wing section is thick, allowing for a deep spar.

I completely stand by my assertion that on a small, cheap, smple flying wing (the Pelican, the Backstrom Plank, the Facet Opal) you will not see a useful benefit from a strut braced wing as shown on the A-12 Bagoas posted above.

I agree that big box spars make the most sense for that sort of approach with a relatively low aspect ratio, relatively thick airfoil, and all or partial contant chord. Remember this…?

FCAD3197-C598-4402-A765-09E02DE22447.jpeg
 
Top