I have been biten again by the tsetse fly

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by berridos, Nov 19, 2019.

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  1. Nov 20, 2019 #41

    Riggerrob

    Riggerrob

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    John Dyke added drooped leading edges to his Dyke Delta to reduce stall speed and landing speed. Many plans-built Dyke Deltas incorporated the leading edge mod.
    Several Mirage III (jet fighter) variants have been retro-fitted with similar, conical leading edge cuffs.
    The basic concept is the same as the Robertson STOL kit, which increases the leading edge radius to smooth airflow and delay stall by a few more knots.
     
  2. Nov 20, 2019 #42

    Riggerrob

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    A few designers have experimented with high winged deltas, but even fewer have succeeded.
     
  3. Nov 20, 2019 #43

    poormansairforce

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    Thats exactly what I was thinking. That would solve the downward view problem.
     
  4. Nov 20, 2019 #44

    Doggzilla

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    And make it vastly easier to get out of. That’s for sure.
     
  5. Nov 21, 2019 #45

    Aerowerx

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    The maximum what is at 42% of what?

    This is incredibly dangerous for any aircraft, tailless or not. A properly designed tailless is no worse than a properly designed tailed aircraft. An improperly designed tailless is just as deadly as a improperly designed tailed aircraft.

    (and it makes it easier to follow the conversation if, when responding to someone, you insert a quote)
     
  6. Nov 21, 2019 #46

    Doggzilla

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    In a tailed aircraft, yes.

    In tailless, the tumble occurs immediately after stall and before it gains airspeed, and the tumble is made worse as airspeed increases. I do not know of anyone who ever recovered from a tumble.
     
  7. Nov 21, 2019 #47

    BJC

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    I’ve met John Moody, very much alive, after watching him tumble in his powered EasyRiser.


    BJC
     
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  8. Nov 21, 2019 #48

    Doggzilla

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    I have already confirmed this 3 times already.

    You asked if it was using MAC/MC and I responded yes repeatedly.

    If you aren’t going to read and make negative assumptions then please stop spamming me. It’s starting to look like you just want to argue for the sake of arguing.
     
  9. Nov 21, 2019 #49

    Aerowerx

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    Again, a properly designed tailless is no worse than a properly designed tailed aircraft. (Reference Nickel's "Tailless Aircraft" book.) The problem is when someone designs a tailless with the "rules" for a tailed aircraft.
     
  10. Nov 21, 2019 #50

    Aerowerx

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    I give up.

    I am not spamming you. I just have a hard time following what you are saying.
     
  11. Nov 21, 2019 #51

    Dillpickle

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  12. Nov 21, 2019 #52

    Doggzilla

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    First off, it was a flat spin. And secondly, he almost died in the impact.

    “Doctors later said Moody suffered a collapsed lung, crushed tailbone and two fractured ankles.

    Compounding Moody's medical problem is the fact that he's not insured. Not only is he unable to pay for all his medical care, but his income dropped to zero the moment his glider impacted the ground.”

    I would not use him as an example if I was you.
     
  13. Nov 21, 2019 #53

    BJC

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    I saw Moody tumble at Oshkosh, recover and land normally. Talked to him about it.

    I know the difference between a flat spin (I’ve done hundreds of them, both stick forward and back) and a tumble.


    BJC
     
    Last edited: Nov 21, 2019
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  14. Nov 21, 2019 #54

    proppastie

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    Looking at the tailless aircraft vs one with the tail.....Lets talk about a properly designed aerobatic biplane ....say like BJC flies .....or any small short-coupled tail-dragger.... Is that as easy to fly aircraft compared to the spam cans most learn in now days?.....properly flown yes it is safe but I would hope most would recognize it takes a lot more practice to fly it safely...... A small short-coupled tailless aircraft.......Be careful out there.
     
  15. Nov 21, 2019 #55

    cheapracer

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    Oh they scary! Every time I see one the pilots are out of control, spinning, going inverted, looping, stalling, **** things never fly straight and even.


    Another Delta type, the Roh 2-175 had quite noticable outer cuffs

    Rohr 2-175.jpg

    I love the Rohr, I would produce similar in a heartbeat. People can argue the merits of the fanjet all day long, but the bottom line is it was designed to take a cheap, stock high revving, car engine, and the fan was all designed by a proper flow aerodynamisist from Garrett (the people who build turbo chargers and jet engine stuff)

    https://fraseraerotechnologycompany.com/Rohr_2-175_Fan_Jet_page2.html

    - any engineer out there who wants to do the numbers for me can earn himself a free one ...

    https://cn.bing.com/images/search?q...Search&qs=ds&form=QBIR&first=1&cw=1129&ch=631
     
    Last edited: Nov 21, 2019
  16. Nov 21, 2019 #56

    berridos

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    With such a large chord it is very easy to achieve laminar flow. Additionally the large thickness and chord allow for an easy implementation of a retractable leading edge slat system, maybe even maintaining laminar flow. However static cuffs are also an interesting option. I am impatient to see the wing profile used.
    In order to hide the tip wheels i was thinking of some type of simplified winglet to retract the wheels into them. What considerations should be accounted for in case of winglets mounted on deltas?
     
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  17. Nov 21, 2019 #57

    proppastie

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    I am sure the list will correct me if I have miss-heard ...but as I understand it the aerobatic aircraft has less built in stability in order to be able to perform aerobatics better.
     
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  18. Nov 21, 2019 #58

    cheapracer

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    You know it was satire ...? :D
     
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  19. Nov 21, 2019 #59

    Riggerrob

    Riggerrob

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    Dogs teeth are common on swept wings for two reasons. First, dogs teeth reduce spanwise airflow. Look at the Mig 15 and 17 jet fighters. They create a vortex that works similar to a wing fence. Even fore-and-aft slots in the leading edge also produce similar pseudo 'wing fences."

    Secondly, dogs teeth allow you to extend the outboard leading edge farther forward, increase leading edge radius and reduce outer wing angle of incidence, all of which help keep the outer wing flying after wing roots have stalled. Burt Rutan noticed this problem on Long Eze and solved it by installing pseudo engine pylons along the leading edge. Velocity canard also suffered similar stable, deep-stall problems because the wing roots stalled after the wing tips. Without the outer wings lifting, Velocity lost a lot of nose-down pitch stability. Fortunately stalled Velocity descended so slowly that the pilot survive a stalled landing into water.

    We also see full-span extended leading edge cuffs on a lot of STOL kits retrofitted to production airplanes.
    A few production airplanes (Cirrus and Kodiak) only have extended leading edges outboard to help maintain aileron control on the edge of the stall.
     
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  20. Nov 21, 2019 #60

    Riggerrob

    Riggerrob

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    Installing larger tail wheels and braking them would do the same as installing tail wheel brakes on a Piper Cub ... not much difference in braking distance.
    Try to think of Verhees Delta as a conventional, tail-wheel airplane with only one main wheel (slightly ahead of the C. of G.) and multiple tail wheels. Since most of the weight is on the main wheel, installing brakes on the main wheel provides the shortest stopping distance.

    As for the suggestion about retracting tail wheels ... Cessna-Columbia, Cirrus, Lancair and RV have all proven that you can cruise at 200 knots with carefully-faired fixed landing gear. Trying to retract wheels on airplanes that cruise less than 200 knots adds so much weight that cruise speed only improves a little, but empty weight suffers (gets heavier). When empty weight suffers, so do useful load and range.
     
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