Is this plane going to fly? I have not flown it yet and thought I would get your thoughts before I try it out. What makes it unique is its wing. The wingspan is 41 inches, chord is 21 inches, and is 6 inches thick at the spars. I call this plane “Fat Boy” because of the really thick wing. The picture doesn’t show the true size of the wing, it is huge. It is a wing with a basement. The plane weighs 9 lbs and has an OS .91 FS for its power. More than likely it will require a 1.20 or larger engine if it does fly. I have been building fun fly planes with thicker and thicker wings so I decided to go all the way with a 6-inch thick wing. I wanted this design to be a really good slow aerobatic plane. The fuse is 12 inches high at the cockpit area and has a ½ inch aluminum channel at the bottom to keep it straight with no warps. The fuse is about 53 inches long. I have Fat Boy balanced at about 23% so I think it is going to be tail heavy for its first flight, but I didn’t want to add any more weight. If the .91 gets it off the ground I am sure it will be a marginal performance.

So see if you can predict if this plane will fly or not and tell me what flight characteristics it will have.

James, it will not fly. Just bring it to me and i will take care of it for you, that way you will not have to worry about it anymore. : )
Kidding aside, should be a hoot to see it fly. Keep us posted on the flights.

gw

GW3D = Gary Wright?

Interesting idea James, i've found that taking an idea to an extreme is a very usefull "thought tool". What i mean is, often, why I'm trying to figure out how some small change might affect something, if i think of a very large change, it's easier to figure out. Not sure I explained myself very well, but it's a technique i use quite often to much success (on many things other than airplane design).

Anyway, i can't make a post without making a prediction right? Well, i'll say it will fly, though i'm really not sure about that one. The airfoil is nearly a circle, lol. If it does fly, i would imagine VERY gentle stalls and low speed flight.

41" is a very small span for a plane that size and weight but i guess any more would be too much drag... given some airspeed it should produce tons of lift though, so it may not be a problem.

oh, and it'll be fun to fly straight down cuz it'll be real slow!

You are worried about fighting tailheaviness? It sounds like you are on target to think that a .91 won't haul the plane around also. Maybe start with a heavier, more powerful engine in the nose like a 120-150 size 4 stroke.

I don't know squat about the dynamics of airfoils, but that sure LOOKS like a curiousity.

I just finished a clipped wing Aeroworks profile Extra. It weighs 9 lbs 8 oz including 3 oz of ballast in the nose . Power is from a YS 120 . For all around fun fly performace the engine is purrrfect. Takeoff vertically, hover all day, great throttle, etc...

-Cheech

Why don't you stick an fan in the wing?
Its big enough.
Check pichure

James,
Well, maybe you'll have knee banging experience like I did with a home built. I built two 'Pen Knife' wings (36" span) with perforated leading edge D-tube covering for lightness, Then I built a modified Pen Knife fuse, and mounted the wings top and bottom, about 8" apart, top wing about 2-3" forward of bottom wing. I enlarged the rudder, mounted four servos with pull-pull on rudder and elevator, mini servo on throttle, and an MVVS40 and minipipe in nose. Thrustline is straight down the midle and hor stab is on t.l. I balanced it right between the spars of top and botom wing, seemed logical to me. First flight, it gets of the runway and sticks the nose straight up, as I give down elev it hesitates, then pitches around to nose down, well, it was walloping along, getting further and further away from me, I was so bussy trying to control it that I couldn't turn it around. I finally get it turned around and 'fly' it towards me and make a successfull landing in the grass. I received standing ovation from everybody else at the field he he. Needless to say, it was VERY tail heavy. I moved the elevator servo forward in the fuse, but it is still extremely tailheavy. It has control interaction like nobodys business, when touching rudder it pitches wildly. It flat spins great, but it is an exercise to fly. The good thing is, that as one gets off the power, it calms right down and glides in for a landing.
I don't know yet if I am going to try to fix this plane or just fly it the way it is, makes everything else easy to fly he he.
DKjens

OOps in my original post I thought you were talking about a flying wing, then I looked at the picture. The plane in the picture looks like it just can't wait to get airborn. Good luck

James, if you balanced the plane at a point 23% of the wing chord back from the front of the leading edge, it is actually nose heavy, not tail heavy. Most of the fun fly planes are balanced at 30-35% back. The nose heavy condition should make it easier to control until you know how it will fly. You may need to add quite a bit of tail weight to move the CG back.

James, i once built a similar plane with only a 3" thick wing. I had a hard time getting up enough airspeed for the tail to start working. The plane was a littl tail heavy and all it wanted to do was hover. One of the first times I flew it, it headed straight for the outhouse and then hovered above it. I had a tough time getting it away from the outhouse. As you can guess, the plane got a name: the Outhouse Special.

I'll be interested to hear your flight report.

Okay I'll play the critic, seems no one else will. Only a good freind will tell you you've got a booger hangin' out of your nose. I don't think the ailerons will be very effective at moderate to high speeds and may be marginal at low speed. The shape of the wing isn't going to allow the boundry layer to adhere at any speed above a walk. Also it looks like the horizontal is in line with the wing with not much moment. That will render the elevator useless in a larger than normal percentage of the flight envelope. Hopefully not when your trying to flare. Take a video camera for first flight we'd like to see it. And it may be your only chance.

that makes the gee bee racer look thin...

James: I predict that your plane will fly with very short take-off and will fly as slow as you want to. It will hover real easy, but roll slow. I don,t think it will handle so bad you will crash it, but it will not snap-roll. Looks like a fun experiment. Thanks CaptinJohn

have you flown it yet?

This photo will show the mass of the wing and fuselage at a better view. No it hasn't been flown as of this time, I am waiting for more predictions.

edh13, the horiz stab is located 1-inch above the center of the wing.

i can't quite make that out, does it say "i eat armadillos for breakfast" ???

Waiting for more predictions?! Go fly!! I'm excited to hear how it goes

I have made once a fun fly with ... let´s say 3/4 of the thickness of yours; now it rest in pieces because it didn´t glide at all!!!! instant break and fall like a leaf, so PLEASE use a ultra reliable engine and a large prop to fly hanging in it (also in level flight not only for hovering).

Go for it and tell us!

can't hurt to try, im sure it should fly

My first thought was that it wouldn't fly at all because of flow separation. After looking at it for awhile, I think it will behave somewhat like a lifting body. You will need a high angle of attack to generate any lift, and lots of power. It may be pretty unstable in pitch around straight and level as the lift goes away. Since it is pretty much flying on the prop, roll stability isn't much of an issue as long as the ailerons will drop easily into the air flow on the bottom of the wing at high alpha. Plan on landing on the tailwheel first with the power at 1/2 throttle. If the tail surfaces are in clean enough air to be effective, it may be kind of 3D-ish

Just my guess.

Okay, I'll say it, it won't fly very good at that weight! How did you manage to get that thing up to 9 pounds? I will make a prediction, first flight will be its last flight. I say that because even if you manage to sucsessfully take off and land it you won't want to fly it again until it goes on a diet. Don't kke us in suspense too long.
Todd.

Okay, I'll say it, it won't fly very good at that weight! How did you manage to get that thing up to 9 pounds? I will make a prediction, first flight will be its last flight. I say that because even if you manage to successfully take off and land it you won't want to fly it again until it goes on a diet. Don't keep us in suspense too long.
Todd.

Mil

It does say “I Eat Airmadillors For Breakfast”. We have a lot of fun fly planes called airmadillors at our field.

Will it fly -- sure.
Will it fly well -- probably not
The drag on a wing that thick will be incredible.
IMO The airflow will disturb the elevator and it will probably be a bit difficult to handle
BUT what the heck, youve allready spent the money and done the work, just go fly it.

I am predicting that the engine will pull it into the air and uncontrolable decent. Please prove me wrong!
Steve

the rest of the plane seems to be very nice... you can still turn to the light side...

best wishes anyway