How does flat foam wing fly? Is it angle of attack?

[DanWard]

I had a shock flyer but that is darn brittle foam

Now I have an EPP which seems more duarble.

Flew the EPP for the 1st time yesterday.

Do all flat foam planes fly with a nose up attitude bacsue there is no lift because of no airfoil?

On some of my other planes with symetrical airfoil I have been playing with balance. When the balnce is right they fly upright or inverted with neutral stick. Sometime I leave them just a tad bit nose heavy which means inverted I have to apply a little down stick to remain level. It keeps me honest.

At least that is wht I think I am doing with my balance. I always fly the maiden with it nose heavy since tal heavy planes seldom fly twice. BUt once I get that out of the way I pursue balnce until as close to neitral stick upright or inverted as I can get. Once complete everything like knife edge flight feels more neutral elevator.

But again, I don't know nothing. I read, try, and think it works.

Then comes flat foam. They always seem to need up trim to maintail levl upright flight. Then when inverted I have to apply a bit of down stick. Result is upright or inverted they always seem to fly with a nose up attitude.

Therefore, not knowing anything, I assume that for flat foa wing to fly there must be some nose up angle of attack.

Can anyone provide any input so I can get past the part of everything being conjecture on my part and where I only think I'm doing the right things?

[JetPlaneFlyer]

A flat plate is just a type of symmetrical airfoil and like any symmetrical airfoil it does need a little positive angle of attack to make lift.

This article may make it clearer : http://www.wattflyer.com/forums/vbgl...y&id=2&catid=4

[DanWard]

Thanks, good article. now understanding most of what I just read...

So with my balsa planes with a pronounced symetrical airfoil I fiddle with balance and trim until it flys pretty much hands off when upright or inverted. And when I look at the elevator after landing there in no perceived up trim.

This must mean it is boardline tail heavy to produce just enough angle of attack either upright or inverted such that the elevator doesn't do much to add to the angle of attack. Does this sound right?

But when I try to apply it to flat foam I never quite get there which means it must still be nose heavy? or while flat is still considered a symetrical airfoil it requires more angle of attack which may never be acheive through balance?

Somthing (probably the loose nut on the keyboard and transmitter) keeping me from getting the same results with flat foam that I am getting with my balsa planes.

[quorneng]

I think you will find that both a symmetrical aerofoil and a flat wing require a positive AOA to create lift but simply a flat wing requires a rather bigger angle.

This requirement may well mean it cannot be set up to fly either way up without re-trimming.

[kyleservicetech]

Originally Posted by quorneng

I think you will find that both a symmetrical aerofoil and a flat wing require a positive AOA to create lift but simply a flat wing requires a rather bigger angle.

This requirement may well mean it cannot be set up to fly either way up without re-trimming.

Just about any flat type of wing can fly with the proper angle of attack, and enough power up front. Its just that airfoils are likely to be more efficient in flight.

Remember those paper airplanes we used to build, or those stick type balsa rubber band models?