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Thread: Swept-forward, shoulder-wing configuration

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    Registered User BBerson's Avatar
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    Re: Swept-forward, shoulder-wing configuration

    How about swept forward low wing? Any Homebuilt ever do that?
    Roncz has it with his design, but I don't think it was built.

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    Registered User cluttonfred's Avatar
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    Re: Swept-forward, shoulder-wing configuration

    There are lots of canopy or cabin top options, right now I am leaning toward a one-piece, forward-hinged bubble or a similar flat-wrap windshield like a Minicab in a composite hood. A light frame carrying a flat wrap up from the fireawall, over the crew and back down to the wing, with either flat or slightly bowed side panelsThe effect would be not unlike a cartoonish Nord looking somewhat rectangular from the front and like the end of a cylinder from the side. Regardless of the canopy design and hinge/door arrangment, the idea would be to have the canopy or cabin top carry back no further than the wing trailing edge to leave the rear fuselage Volksplane simple.
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    Re: Swept-forward, shoulder-wing configuration

    The Volksplane is low wing. Did you consider sweep forward on a Volksplane?

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    Re: Swept-forward, shoulder-wing configuration

    There are lots of canopy or cabin top options, right now I am leaning toward a one-piece, forward-hinged, blown bubble or a simiar flat-wrap windshield like a Minicab in a composite hood. A light frame carrying a flat wrap up from the fireawall, over the crew and back down to wing might work, with either flat or slightly bowed side panels. The effect would be not unlike a cartoonish Nord looking somewhat rectangular from the front and like the end of a cylinder from the side. Regardless of the canopy design and hinge/door arrangment, the idea would be to have the canopy or cabin top carry back no further than the wing trailing edge to leave the rear fuselage Volksplane simple.


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    Re: Swept-forward, shoulder-wing configuration

    Just read this thread for the first time because forward sweep doesn't appeal to me. What I get from it is that "shoulder" wing is an incorrect definition. In all models show, the wing is indeed, level with the pilots head. Maybe the definition is applied to the airframe in some mysterious way. Personally, I would lower all those wings to the pilots shoulders and sweep the L.E. back. This still gives good over and under wing vision plus removes, to some extent, the possibility of head damage.



    OPPS, Hugh Lorimer design shouldn't be there. That's a mid-wing design.
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    Fly safe.

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    Re: Swept-forward, shoulder-wing configuration

    Quote Originally Posted by FritzW View Post
    I think Aerowerx is building a J-1 but with a T tail like the this.
    Yep!

    I am not changing the position of the wing:


    (I had a better picture than this, but had to delete it when I noticed it was copyrighted.)

    Notice that the wing is at eye level but, because it is a pusher, the pilot's head is actually at or maybe a bit ahead of the leading edge---clear visibility to the sides. I have put a lot of thought into this configuration and, IMHO, it will give the least vision blockage by the wing.
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    Re: Swept-forward, shoulder-wing configuration

    Deleted---duplicate post
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    Re: Swept-forward, shoulder-wing configuration

    Quote Originally Posted by Aerowerx View Post
    Yep!

    I am not changing the position of the wing:

    (I had a better picture than this, but had to delete it when I noticed it was copyrighted.)

    Notice that the wing is at eye level but, because it is a pusher, the pilot's head is actually at or maybe a bit ahead of the leading edge---clear visibility to the sides. I have put a lot of thought into this configuration and, IMHO, it will give the least vision blockage by the wing.
    Neat design, Aerowerx, looking forward to seeing your progress but I am not looking for a pusher right now.

    Deskpilot, I am not sure if there is an "official" definition of a shoulder wing. Low- and high-wing are pretty clear but mid-wing and shoulder-wing are a little fuzzy. Personally, I suppose I'd say that if the wing is above the pilot's head it's a high wing, at or below the level of the pilot's rear end it's a low wing, from the waist to below the shoulders a mid-wing and around the shoulders or even with the head a shoulder wing. Your mileage may vary.... ;-)

    Personally, I would lower all those wings to the pilots shoulders and sweep the L.E. back.
    I think you're missing the point here that the wings are being swept forward to keep the CG in the right place in relation to the wing since the spar can't actually pass through the pilot. You can certainly put the pilot behind the main spar in a mid- or shoulder-wing, but visibilty is poor (see a Mini-Max, for example). Sweeping the wings back in the designs mentioned above would make things worse. I could even see using forward sweep in a light low- or high-wing design for better visibility and, in the low wing, to leave some space below the seats for energy absorption in a crash.
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    Re: Swept-forward, shoulder-wing configuration

    Quote Originally Posted by Topaz View Post
    As far as I know, the "objections" to this configuration are:

    1) Limits visibility directly to the side, and

    2) "It looks weird".

    In terms of marketing, the second factor is by far the largest, by orders of magnitude. I've never heard of any particular safety issues regarding the aircraft listed. You might try contacting SVSUSteve via PM, and see if he has any data about this aspect.
    Forward sweep is really efficient...and MFI-9 and Planik sail planes look awesome.

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    Re: Swept-forward, shoulder-wing configuration

    I am working in a forward sweep wing, but in this case the the wing is high. I think that rear window may be a escape gate for problem of getting out when the aircraft is upside down.



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    Re: Swept-forward, shoulder-wing configuration

    ...pretty!
    Iēsous Christos, Theou Yios, Sōtēr

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    Re: Swept-forward, shoulder-wing configuration

    There is the Aeroprakt A22, one of the more popular microlight aircraft.

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    Re: Swept-forward, shoulder-wing configuration

    .... ;-)

    I think you're missing the point here that the wings are being swept forward to keep the CG in the right place in relation to the wing since the spar can't actually pass through the pilot. You can certainly put the pilot behind the main spar in a mid- or shoulder-wing, but visibilty is poor (see a Mini-Max, for example). Sweeping the wings back in the designs mentioned above would make things worse. I could even see using forward sweep in a light low- or high-wing design for better visibility and, in the low wing, to leave some space below the seats for energy absorption in a crash.[/QUOTE]
    .................................................. .................................................. .................................................. .................................................. .......................... Yes, the key motivation (for forward-swept wings) is getting the main wing spar aft of the pilot's spine. Lots of two-seater gliders have ) slightly forward-swept wings to allow the rear passenger to sit exactly at the center of gravity (measured at his belt buckle). Note that the RV-12 is able to do the same thing with a straight wing spar, and constant-chord wing. I suspect that Vans was able to do this because their Rotax 914 engine weighs less than the Lycoming installed in the Bolkow Junior. One disadvantage is the (RV-12's) poor down-wards visibility created by the low wing. Shoulder mounted wing provides the best compromise for visibility. Because the pilot's eyes are above the wing, he can keep the runway in view while turning onto final (better than the factory-installed blind spot on Cessnas). OTOH, he can also peek under the wing for sight-seeing (much better down-ward view than an RV-12). Forward sweep is a structural compromise to keep the center of lift in line with the center of gravity (pilots' belt buckles). Minor forward sweep improves stall characteristics (over a straight wing) because turbulence migrates towards the wing roots. Wing roots stall first, leaving smooth air flow for aileron control even when the wing is partly stalled. Forward sweep is slightly de-stabilizing, so Bolkow Junior etc. tend to have a degree or two more dihedral than similar high wings.

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    Re: Swept-forward, shoulder-wing configuration

    For the record, my project will probably require a forward sweep also. it currently shows a straight wing (see CAD pics of my project) as I have not yet resolved weight/balance/c of g. This will be out of necessity although I do prefer the aesthetics and characteristics of this feature. It is a 'high-wing' config, but I can put a clear canopy-extension back to the spa if I desire.
    The wing also has a cross-tie at the trailing edge to reduce the possibility of fold in unfortunate circumstances..... (15 minutes)
    Autopilot

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    Re: Swept-forward, shoulder-wing configuration

    Reviving an early thread and in conjunction with some recent threads, here is an original 1959 article by designer Bjorn Andreasson on his BA-7, the relatively simple homebuilt (note the uncowled engine and straight rudder) that went on to sire the Malmö MFI-9/Bölkow Bo 208 and to inspire the related Saab and Pakistani designs. I keep coming back to this configuration in my doodles and daydreams for some reason.

    The BA-7 - Bjorn Andreasson - Sport Aviation - 1959_07_03.pdf
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