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Flying wing as cheap and simple option for basic fun flying.

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rotax618

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Mike’s plank certainly is impressive, the down side to converting it to tractor would be pilot downward vision, as we have discussed before. I think if you want a tractor plank you have to think outside the box and put the wing over the pilot or provide transparent covering to the floor, there may be more solutions like rear engine shaft drive tractor or twin electric tractor engines with rear mounted batteries.
 

erkki67

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Sockmonkey had a good start, what about a parasol
lay-out with a sit on top?

mike has a wing that flys.

i came across this following concept of Alexander Lippisch;

DFS-193 - DFS 193 – Wikipedia.png

i could like the fuselage of the Piojo, with the wing of MikeW:

A8E5D862-C2E0-4729-BE1A-6DC33061AE0B.jpeg

a 3-piece wing with Elevons and wingtip Kasperwing spoilers style.
 

Speedboat100

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Sockmonkey had a good start, what about a parasol
lay-out with a sit on top?

mike has a wing that flys.

i came across this following concept of Alexander Lippisch;

View attachment 102628

i could like the fuselage of the Piojo, with the wing of MikeW:

View attachment 102629

a 3-piece wing with Elevons and wingtip Kasperwing spoilers style.
How is the top wing going to stay stable ?

Or is it hinged ?
 

rotax618

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As has been discussed, the only problem with that layout is the thrust/drag couple and access under a wide chord LA wing. Neither is a deal breaker, being a sit on rather than sit in would make access easier and a higher thrust line with the engine on a mount similar to the HM14 would solve the thrust line problem.
I recon that since you have a fuselage, why not just retain the fin and rudder for yaw, it would be behind the wing and thus far more effective than tip spoilers - elevons would be OK.
 

Speedboat100

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As has been discussed, the only problem with that layout is the thrust/drag couple and access under a wide chord LA wing. Neither is a deal breaker, being a sit on rather than sit in would make access easier and a higher thrust line with the engine on a mount similar to the HM14 would solve the thrust line problem.
I recon that since you have a fuselage, why not just retain the fin and rudder for yaw, it would be behind the wing and thus far more effective than tip spoilers - elevons would be OK.

I would also widen the fuselage 4 inches and get the legs outa slipstream.
 

erkki67

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As has been discussed, the only problem with that layout is the thrust/drag couple and access under a wide chord LA wing. Neither is a deal breaker, being a sit on rather than sit in would make access easier and a higher thrust line with the engine on a mount similar to the HM14 would solve the thrust line problem.
I recon that since you have a fuselage, why not just retain the fin and rudder for yaw, it would be behind the wing and thus far more effective than tip spoilers - elevons would be OK.
For a sit on top Version beneath the wing, the access is a non issue.

for the directional controls, either system would work, the central fin or my idea of Kasperwing spoilers.
 

erkki67

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Henryk published the link of Kasperwing, from which I took following picture;
Image PNG.png
the soul of this bird is on the right track, but as said, with the the engine location and fuselage type of the Piojo, and a similar wing or the wing of MikeW, 3 piece strutbraced and the Kasperwing spoilers.
 

rotax618

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Evans Head Australia
The Kasperwing spoilers work because the wing is swept, they may not be as effective on a plank unless the AR was very low. In any case a reasonably large scale model may answer the question.
 

cluttonfred

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That Lippisch design is neat, not unlike some of the Westland Pterodactyl types, and might have had military applications back in the 1930s or 1940s since a rear gunner would have had a great field of fire. That said, the wing is needlessly complex for sport plane and the ground angle for taxiing would have been very steep with poor visibility. A simple swept constant-chord wing with outboard elevons, pilot in the rear, and tricycle gear would make more sense for a sport plane. Even better, go with a single-seater or side-by-side two-seater with all the crew weight at the CG. Here's a quick sketch though I didn't change the gear.

HBA concept sketches (8).jpg

i came across this following concept of Alexander Lippisch;
 

Riggerrob

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Canada
Yes dear cluttonfred,
Some of those gull-wings built by PZL and Westland during the 1930s were ridiculously complex.
Your sketch is a good attempt at simplification, but I would add extra-large elevons (ala. BKB) to improve pitch stability and control.
 

cluttonfred

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Yup, it was just a quick sketch, extended-chord elevons as recommended by Al Backstrom based on his plank experience would help, not just for pitch authority but also to leave more of the wing to reach max CL and not be washed out by the elevons.

Alternatively, you could go with identical-section but separate flaps and elevons over the full span with the flap span adjusted for near-neutral impact on pitch when deployed and just use whatever span is left for the elevons. That latter idea would likely require more sweep to get enough flap area to be worth it.
 
Last edited:

Riggerrob

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All this discussion of swept wings and ring wings makes me think that the middle of the wing contributes little to stability or control. It seems to be little more than a convenient place to install wings spars and hide pilots.
OTOH if you follow Barnaby Wainfain's logic, the huge Reynolds numbers created by the long root chord help improve lift to drag ratios.
Finally, consider how few homebuilders can accurately build wings with chords smaller than a metre or a yard.
 

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