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

rotax618

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Oct 31, 2005
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1,127
Location
Evans Head Australia
It seems to me the choice is high front wing with Flea pitch control (a proven stall proof method) or low wing canard elevator pitch control (not so stall proof).
 

cluttonfred

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Feb 13, 2010
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Fort Walton Beach, Florida, USA
Uh oh, here we go again. ;-)

Actually, front wing low or high and pitch control on the front or rear wing can all work and provide stall resistance or at least docile low-speed handling. The key is using identical or at least very similar airfoils and chords and respecting the "150% rule" for loading the front wing more than the rear so it always has to stall first.

I have often wondered about using inboard elevators and outboard ailerons all on the front wing and no control surfaces at all on the rear one, or perhaps tapered elevons on the front wing that would force a progressive root-first stall at high angles of attack. The effect would be something like the Gatard Statoplan, which looks like a conventional monoplane but climbs and descends using flaps with a fixed horizontal stabilizer moving only slightly for trim purposes.

It seems to me the choice is high front wing with Flea pitch control (a proven stall proof method) or low wing canard elevator pitch control (not so stall proof).
 

Groundhog Gravy

Active Member
Joined
Apr 20, 2019
Messages
30
I believe that the limitations of the forum software prevented me from enforcing the “pick one in each of four categories) so some people may have messed that up, hence the discrepancies.
In fact, I know I did not pick an option between conventional and trigear.
 

Sockmonkey

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Joined
Apr 24, 2014
Messages
2,217
Location
Flint, Mi, USA
Uh oh, here we go again. ;-)

Actually, front wing low or high and pitch control on the front or rear wing can all work and provide stall resistance or at least docile low-speed handling. The key is using identical or at least very similar airfoils and chords and respecting the "150% rule" for loading the front wing more than the rear so it always has to stall first.

I have often wondered about using inboard elevators and outboard ailerons all on the front wing and no control surfaces at all on the rear one, or perhaps tapered elevons on the front wing that would force a progressive root-first stall at high angles of attack. The effect would be something like the Gatard Statoplan, which looks like a conventional monoplane but climbs and descends using flaps with a fixed horizontal stabilizer moving only slightly for trim purposes.
I've had thoughts along those lines. Though in my case, it focused on the fact that using full-span elevons on the the low fore wing meant that control runs would be simple. The stick would be mounted right where nubs at the base of it could plug right into the elevon control horns.
 

Sockmonkey

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Apr 24, 2014
Messages
2,217
Location
Flint, Mi, USA
Having the high aft wing be a delta seems like a good match to me.

A delta needs to be lightly loaded for a good L/D ratio and the aft wing on a tandem needs to be loaded lightly for stall prevention and pitch stability. The needs line up.
The delta being high combined with it's swept leading edge gives enough effective dihedral that the lower front wing can be straight.
 

Sockmonkey

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Joined
Apr 24, 2014
Messages
2,217
Location
Flint, Mi, USA
Yes a delta rear wing would ensure that the rear stall was delayed, It is sort of becoming a delta canard.
Yep. Rutan make some, but his always had the little canard so the lift efficiency suffered.

You could go really nuts and use a lifting delta body like the facetmobile with a Pou-type fore-wing high mounted on struts.
 

erkki67

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Joined
Feb 18, 2010
Messages
2,456
Location
Romont / Fribourg / Switzerland
Having the high aft wing be a delta seems like a good match to me.

A delta needs to be lightly loaded for a good L/D ratio and the aft wing on a tandem needs to be loaded lightly for stall prevention and pitch stability. The needs line up.
The delta being high combined with it's swept leading edge gives enough effective dihedral that the lower front wing can be straight.
And if you used the forward wing on the rear position and my preferred narrow fuselage?

construction would be by far easier.
 
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