Aussie Plank

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by rotax618, Nov 28, 2019.

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  1. Nov 28, 2019 #1

    rotax618

    rotax618

    rotax618

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    I posted these photos on another thread relating to the Winton Opal, but I think it is interesting enough for a thread on its own.
    The photos were captured stills from an old video “Australian Ultralights and their Pilots”, I visited the builder many years ago and inspected the machine - I’m not sure he is still alive as he was more ancient than myself at the time. The airframe is/was in a hangar at South Grafton NSW Australia.
    The aircraft is probably classed as a pusher Plank rather than a “Prop in slot” even though the elevator is behind the prop. The engine was an inverted 60hp outboard marine engine using direct drive, the builder estimated 40hp in that configuration, he said that the engine was pretty unreliable which stopped him doing more flight testing.
    He reported that the takeoff run was a short 150metres and a similar landing distance, the Plank displayed no vices and had no discernible stall, only a higher sink rate.
    The airframe was extremely simple and used a single 100mm tube spar and ply ribs.
    I don’t know who I could contact to get permission to put that part of the video on youtube. F7CA16D8-04AA-41C0-95BF-C68BD7918BBF.png E3F45170-F4F4-4625-8871-7EF588FB2378.png 5669628B-5F5F-4FD9-A2BB-35DD7AD80D34.png C281AEAD-17DE-4F32-80DC-269113A65C3D.png EDB5E7AB-A24A-4368-98CB-387E8B3C9E92.png 583EC46F-FB2F-42BE-BC83-FF64BBB6955C.png D43D3CFE-E98E-4E4A-8A6E-16240AFC3717.png A7F8F5F8-FEDB-4F80-BA19-CA79009E55C2.png 382B757F-A704-49AC-9387-73ECE03CFBC3.png
     
  2. Nov 28, 2019 #2

    plncraze

    plncraze

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    Thanks for sharing! The folks who understand flying wings and build and fly them considered them safe machines. The airfoil looks like an inverted normal airfoil. Those are great pictures too. That reminds me of the Skyjacker which now tests in a storage lot. My guess is your builder controlled weight better. Between your creations and the others you find you share some neat machines here. Thanks again!
     
  3. Nov 28, 2019 #3

    BJC

    BJC

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    I thought that it looks like a symmetrical section.


    BJC
     
  4. Nov 29, 2019 #4

    cheapracer

    cheapracer

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    I concur, with a little reflex via the ailerons.
     
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  5. Nov 29, 2019 #5

    Mike W

    Mike W

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    Very interesting. I haven't seen this one before. Has he got a rudder on the aircraft, or if not how does he achieve yaw control?
     
  6. Nov 30, 2019 #6

    rotax618

    rotax618

    rotax618

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    There is/are no rudder/s, only endplates on the wingtips, the builder said that it didn’t need rudders the turns are perfectly coordinated, the tricycle UC would help with X-wind landings. I suppose it would fly like a “bank and yank” flying wing model.
     
  7. Nov 30, 2019 #7

    Topaz

    Topaz

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    Personally, I'd want a little more rudder authority on this thing. Other than that, it's an extremely simple, quick-build sort of aircraft. The only performance metric it'll destroy is "speed of build", but that's okay, too.
     
    Last edited: Nov 30, 2019
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  8. Nov 30, 2019 #8

    Mike W

    Mike W

    Mike W

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    My plank tends to weather cock into wind as soon as it lifts off. See test pilots report under thread "Plank progress". At present I am doubling the opening of the drag rudders and also making them open together and reduce the landing distance caused by a low drag aircraft.

    You have set me thinking that weather cocking on the MW9 is caused by the large aft mounted fins and may be reduced by fitting end plates.

    Otherwise the elevons give adequate control for normal flight. We need to modify the model and try it with end plates.
     
    Last edited: Nov 30, 2019
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  9. Nov 30, 2019 #9

    Tony Spezio

    Tony Spezio

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    Interesting plane. Thanks for the photos.
     

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