Duncan's got a Flea

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by rtfm, Aug 3, 2017.

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  1. Sep 26, 2017 #441

    bmcj

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    Flying Flea Flop... Too bad this wasn't in Florida... I could have really rocked the caption. It would have been Flantastic!

    From what I've read since (if it is accurate), this particular build seems to be as much an 'art project' as it is an 'aircraft'. Built by an artist from wood and covered in newspapers.

    IMG_8868.jpg
     
  2. Sep 26, 2017 #442

    Victor Bravo

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    Under all that newspaper, the airplane appears to have been well built. It has the newer non-pointy airfoil, and it does not look (from this one photo) to have been kluged together.

    Kown or Matthew (our resident Flea authorities) do you guys know anything baout this particular aircraft?
     
  3. Sep 26, 2017 #443

    pictsidhe

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    Can I hear pitchforks being sharpened? Is that flaming torches that I can smell?
    Anway, back to ailerons. Has the Mignet Inquisition eradicated all traces of aileroned fleas over the years? Maybe, occasional people tried them then stopped bothering? After 80 years of prolific Pouing, you'd have thunk that if ailerons added much to the Flea-mula, you'd hear about them. While I don't favour them myself, I'm kinda wanting someone here to build a 3-axis flea and compare it t a 2-axis one to see if all the fuss about it has any merit. The dual Croses controls sound like an interesting experiment.
     
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  4. Sep 26, 2017 #444

    pictsidhe

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    Looks like a 2CV engine with chain reduction. Why did it stop flying?
     
  5. Sep 26, 2017 #445

    cluttonfred

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    From what little you can make out in the video, it looks like the engine was not developing much power, which might also mean a mismatched prop, and/or the plane was overweight. There have certainly been plenty of light homebuilts flown with the little Citroen or DAF two-cylinder engines.
     
  6. Sep 26, 2017 #446

    nestofdragons

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    3 Axis vs 2 Axis. To me it sounds like: A solution looking for a problem. The following bikes were probably designed the same way.
    solution.jpg solution02.jpg

    Well, if you want a 3 axis, create one. But ...please ...stop saying that the 2 axis Flying Flea was not good. It flies good. It is as stable as a Weedhopper. But ...don't compare it with a Glassair for example. Totally different stuff. But ...also don't think that a Flying Flea is only for slow flight. Guy Francois was busy designing a speedy Flying Flea. He did some windtunnel tests with his design. Seemed like promising. But ...his old age will make that he will never be able to finish the idea. Sad. Speed and easy to steer. Would have been wonderful.
     
  7. Sep 26, 2017 #447

    Topaz

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    Here's the thing: I don't think anyone has been saying that they're "no good." Just because they're not as suited to the style of airports we have here - universally long, skinny runways as opposed to the more-common "open field" of Europe - doesn't mean they're "no good". Crosswinds, sometimes strong and gusty, are a fact of life here, and two-axis airplanes have not caught on as a result. Not just the Pou, but also the Ercoupe and other attemps at two-axis aircraft.

    Nothing is wrong with them. They're just not well-suited to the kind of operations that are nearly universal here. Adding a feature - ailerons, for full three-axis control - isn't saying that the two-axis version is bad. It's saying we need something a little different here.

    I didn't see ANYONE saying the two-axis Pous were "no good". Perhaps a little less sensitivity is in order.
     
  8. Sep 27, 2017 #448

    Aesquire

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    I know, I was an acolyte of something at one time, then grew up. ;) it was a joke.

    The point was that I am now very interested to see a 3 axis version and see if it's compromises are notable better than the 2 axis version.

    The good points of the Pou include the small work area and compact nature, even trailerable. It pays for the low AR wings in performance.

    Do ailerons HURT any aspect of the design, besides weight and complexity?
     
  9. Sep 27, 2017 #449

    Aesquire

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    The video of the newspaper Pou seems a simple stall with a very marginal engine. It's hard to tell if there's a loss of power before stall. If the pilot had kept the nose down I suspect it would have bumbled along in ground effect, but no higher.

    ( overweight, underpowered, and draggy airplane? Been there, skimmed that. )
     
  10. Sep 27, 2017 #450

    BBerson

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    It only had enough thrust to lift off while going downhill.
     
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  11. Sep 27, 2017 #451

    Thunderchook

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    My sentiments exactly!
    I asked several times "Is the objection to ailerons on a Pou simply religious, or is there a real, practical deficit (or indeed danger) to changing the design?"
    I concluded that no, there appears to be no real, practical deficit to adding ailerons.

    Anyway, we will see a working example as soon as Duncan finishes his in a few months.
     
  12. Sep 27, 2017 #452

    rtfm

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    In a few months? HA! I can't even find 4130 or 7075 sheeting. Well, I can, but at a huge price.

    Seriously, though, I'm making progress slowly.

    Duncan
     
  13. Sep 27, 2017 #453

    MadRocketScientist

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    Have you considered getting the 4130 in from Aircraft spruce or would that still be too expensive?
     
  14. Sep 27, 2017 #454

    rtfm

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    ACS wants $168 just to freight it here.
     
  15. Sep 27, 2017 #455

    MadRocketScientist

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  16. Sep 27, 2017 #456

    nestofdragons

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    I am sure that adding ailerons will make quick reactions possible. The rudder alone kicks in a bit slow. That is what i read. During that flight i did in HM1000, i did not feel that due the fact that i was making slow turns.

    But i wonder. How would the airplane react if ailerons are working in beginning of turn and ... with some delay the roll effect of the rudder steps in. Will it create too much roll? How will the pilot react? Will he reduce the ailerons or the rudder? I think he would reduce ailerons. You have same thought?
     
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  17. Sep 27, 2017 #457

    TFF

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    There is way too much auto racing in Australia to not be able to find something acceptable.
     
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  18. Sep 27, 2017 #458

    Tiger Tim

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    I have no reason to believe that it would be flown significantly differently than, say, a Cub. Ailerons and rudder together in a coordinated manner, not rolling the plane one way then klomping down on the rudder pedal.
     
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  19. Sep 27, 2017 #459

    bmcj

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    That's not a lot when compared to the total cost of the build.
     
  20. Sep 27, 2017 #460

    bmcj

    bmcj

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    I'm not intimately familiar with the Flea's aerodynamics, but if the wing provides a safe stall progression, then adding ailerons MAY disrupt that effect.
     

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