Wing/paint protection film???

Discussion in 'General Experimental Aviation Questions' started by Rik-, Oct 13, 2019.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Oct 15, 2019 #21

    BBerson

    BBerson

    BBerson

    Well-Known Member HBA Supporter

    Joined:
    Dec 16, 2007
    Messages:
    12,057
    Likes Received:
    2,353
    Location:
    Port Townsend WA
    Not separation. It would trip the laminar flow to turbulent. Separation is much worse.
     
  2. Oct 15, 2019 #22

    pfarber

    pfarber

    pfarber

    Well-Known Member

    Joined:
    Feb 21, 2019
    Messages:
    292
    Likes Received:
    15
    Location:
    Pennsylvania
    So bad designs are bad? If you design a plane where any separation of flow causes anything near these conditions then its a BAD DESIGN. The wings should be scrapped and a new profile selected. In the certified world this would have been AD's in a hearbeat, but E/AB allow it for reasons???
     
  3. Oct 15, 2019 #23

    Hephaestus

    Hephaestus

    Hephaestus

    Well-Known Member

    Joined:
    Jun 25, 2014
    Messages:
    1,179
    Likes Received:
    258
    Location:
    YMM
    Probably shows there's less bugs and risk of rain in Nevada... QAC did release the new canard airfoil templates and direct builders to switch to it in the newsletters.

    So effectively they did as they should have.
     
  4. Oct 15, 2019 #24

    BJC

    BJC

    BJC

    Well-Known Member

    Joined:
    Oct 7, 2013
    Messages:
    9,560
    Likes Received:
    6,331
    Location:
    97FL, Florida, USA
    Yes, Experimental-Amateur Built allows it. There is no reason for regulators to have control of such issue.


    BJC
     
  5. Oct 15, 2019 #25

    Rik-

    Rik-

    Rik-

    Well-Known Member

    Joined:
    Sep 14, 2019
    Messages:
    254
    Likes Received:
    49
    Location:
    California
    This is why they put VG's on the GU wing design. Also why the value of a Q2 with an GU wing is so low. It's a **** load of work to create new wings. (Kinda leads to my other post about cold molding)
     
  6. Oct 16, 2019 #26

    Marc Zeitlin

    Marc Zeitlin

    Marc Zeitlin

    Well-Known Member

    Joined:
    Dec 11, 2015
    Messages:
    496
    Likes Received:
    681
    Location:
    Tehachapi, CA
    Feel free to take it up with Burt. Many gliders with laminar flow airfoils have similar issues (and the GU was originally designed as a glider airfoil) - it all depends on what your goal is.

    And that's why many Long-EZs, some Variezes and COZY IIIs, and ALL COZY MKIV's have the Roncz canard airfoil, which, as I stated, does not exhibit the pitch trim change tendency when contaminated.

    You do know what the "E" in "EAB" stands for, yes? As much as I want folks to be safe, I also like the fact that the FAA allows me (or anyone else) to build something that will kill them, or just act funny, if they're not smart about it.

    For $25 worth of materials in VG's and a knot or two on the top end, the GU canard can be made to act perfectly reasonably, even when contaminated, just like the Roncz. It's hardly a catastrophe. If some folks choose not to do that, that's their prerogative. And folks with GU canards know not to put paint stripes or tape near the leading edge, which is what the original question was.
     
  7. Oct 22, 2019 #27

    Victor Bravo

    Victor Bravo

    Victor Bravo

    Well-Known Member

    Joined:
    Jul 30, 2014
    Messages:
    6,086
    Likes Received:
    4,866
    Location:
    KWHP, Los Angeles CA, USA
    Some aircraft are highly specialized machines where almost everything "normal" is pushed aside for some performance or capability gain. The origins of the Quickie were a pursuit of just that; maximum speed and range on the lowest horsepower and fuel burn. The Pitts Special E-AB pushes everything aside for maximum aerobatic performance and control response. Our old racing sailplanes pushed almost everything aside for lowest drag, including the use of hyper-sensitive airfoils. And those airplanes were mostly certified to tougher standards than FAA Part 23!
     

Share This Page



arrow_white