Tandem-wing LSA/microlight concept and poll

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Which tandem-wing configuration would interest you the most (pick one in each of four categories).

  • A1 - High wing forward, low wing aft (Flying Flea) OR

    Votes: 18 37.5%
  • A2 - Low wing forward, high wing aft (Quickie);

    Votes: 26 54.2%
  • B1 - Two-axis controls (no rudder pedals like an Ercoupe) OR

    Votes: 9 18.8%
  • B2 - Three-axis controls (with rudder pedals like a Cessna);

    Votes: 34 70.8%
  • C1 - Conventional (taildragger) gear OR

    Votes: 23 47.9%
  • C2 - Tricycle (nosewheel) gear;

    Votes: 20 41.7%
  • D1 - Tractor engine (engine and propeller at front) OR

    Votes: 32 66.7%
  • D2 - Pusher engine (engine and propeller at rear);

    Votes: 13 27.1%

  • Total voters
    48

delta

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May 26, 2011
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2,448
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Brookside Utah
My avatar is a tandem wing and my user name is delta. What I did was split a delta horizontally with a 108* le sweep, and a 130* te sweep, limit the ws to 216" (18'), and use mostly flat plate surfaces, to wind up with something like this...

twlsa11a.JPGtwlsa11b.JPGtwlsas11a.JPG

Who knows if it'd work good, but it's fun to think about...
 

Aesquire

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Jul 28, 2014
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2,793
Location
Rochester, NY, USA
I've been looking at the sailcloth laminates reinforced with aramid fibers currently in vogue with Hang Gliders and Trike wings.

A Tube frame, ( tube & gusset, welded steel, glued composites ) with a sewn or glued? transparent "cloth" over the framework should be perfect for some of the Low AR "Facetmobile inspired " designs. Windows? The whole thing is window. Of course the cost would lean me towards conventional Dacron for the wing & fuselage etc. parts that a transparent film wouldn't be worth using, but the whole floor, sides, and top of the cockpit would be nice. Or go full transparent Wonder Woman!
 

rotax618

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Oct 31, 2005
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1,127
Location
Evans Head Australia
That would certainly work for a very light faceted design, have to think about the best method of fixing the covering to the tubes.
 

Aesquire

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Jul 28, 2014
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2,793
Location
Rochester, NY, USA
I'm going to assume that glue won't work well until samples are tested.
So sewn sleeves, mostly just loops a few inches wide, attached to a reinforcing strip along the tube would work. That requires assembly of the frame and covering together, so glued joints & carbon tubing? Velcro would work too if you assemble the frame first but would add weight.

Heading that Velcro "ripping" sound might become traumatic. ;)
 

rotax618

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Oct 31, 2005
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1,127
Location
Evans Head Australia
Perhaps strips sewn down the centre, glued and stitched to the tubes should work - belt and braces, The strips could be made from material which is better for glueing ie. canvas.
 

Sockmonkey

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Apr 24, 2014
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2,217
Location
Flint, Mi, USA
My latest notion.
3-axis with a forward monowheel and skids at the tips of the aft wing.
Fuselage and wings are simple shapes, so not to complicated to build.
Might be able to make the fore wing removable without having to unhook and control runs because the yoke is right there and be part of the removable wing assembly.
Entry would be easy. Just make that bit of the delta sturdy enough to use as a step.
The delta is the main structural frame of the plane, with the upper part of the fuselage being mostly for streamlining, so the canopy could open all the way down so you don't have to climb over a sidewall.
Only serious downside is the fore wing blocking landing visibility.
It should be possible to look under the wing on either side well enough to land safely, but some pilots would still be bothered by that.

 

cluttonfred

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Feb 13, 2010
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8,290
Location
Fort Walton Beach, Florida, USA
It's a neat concept and I think it could work, perhaps by raising both wings (assuming the gap is calculated) so that the delta becomes a midwing just below the cockpits and the canard becomes an unbroken wing tip to tip raised up on struts.

That said, I think you would not find many takers, it's just too odd with no obvious significant advantages (like some concepts I have explored, I admit). Why not go with a double-delta like a Saab Viggen or or something like that which coud perhaps achieve similar goals with more "sex appeal"? Here's a sketch.

Untitled presentation (3).jpg
 

rotax618

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Oct 31, 2005
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1,127
Location
Evans Head Australia
Matthew your concept would work better if the canard was not swept, like the Rutan types, an unswept canard would ensure that it stalled first while the main wing had vortex lift at high alpha. I think the fighters with the delta canard are simply Deltas with a de-stabilising fore-plane to ensure ultimate manoeuvrability, not something you would want on a sport plane.
 

cluttonfred

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Hmm, my understanding with the Saab Viggen was that the combination gave decent STOL (a relative term for a jet fighter) performance for takeoff from stretches of Swedish highway since a pure delta wing can’t really use flaps.
 

Sockmonkey

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Joined
Apr 24, 2014
Messages
2,217
Location
Flint, Mi, USA
It's a neat concept and I think it could work, perhaps by raising both wings (assuming the gap is calculated) so that the delta becomes a midwing just below the cockpits and the canard becomes an unbroken wing tip to tip raised up on struts.

That said, I think you would not find many takers, it's just too odd with no obvious significant advantages (like some concepts I have explored, I admit). Why not go with a double-delta like a Saab Viggen or or something like that which coud perhaps achieve similar goals with more "sex appeal"? Here's a sketch.
Most of these started out as purposely going different for the sake of different, but some have merit.
This one hits most of the markers for what people want in a small plane.
Stall and spin resistance.
Compact without sacrificing aerodynamic efficiency.
Structurally simple to make, composed of a few basic forms.
Few moving parts.
Monowheel gear for crosswind landings.
Easy to get into.
 

cluttonfred

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Feb 13, 2010
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8,290
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Fort Walton Beach, Florida, USA
Monowheel gear even though set up as a taildragger is also unlikely to ground loop. The point of ground contact while forward of the CG is so close to it that there is very little lever arm, unlike conventional gear when one wheel digs in.
 

rtfm

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Joined
Jan 3, 2008
Messages
3,532
Location
Brisbane, Australia
Hi,
Thanks for this. In a flutter of wine-induced speculation late last night, I had the idea of a monowheel Fleabike, which could be parked with a sidestand... Ha ha.
 

poormansairforce

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Joined
Mar 28, 2017
Messages
1,129
Location
Just an Ohioan
It's a neat concept and I think it could work, perhaps by raising both wings (assuming the gap is calculated) so that the delta becomes a midwing just below the cockpits and the canard becomes an unbroken wing tip to tip raised up on struts.

That said, I think you would not find many takers, it's just too odd with no obvious significant advantages (like some concepts I have explored, I admit). Why not go with a double-delta like a Saab Viggen or or something like that which coud perhaps achieve similar goals with more "sex appeal"? Here's a sketch.

View attachment 112036
Me likey! I may have draw this up in SketchUp and make a foamy. A straight wing with add on strakes to help prevent main wing stall.....
 
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