Hi everyone!

Here's a quick question for ya. If you have two similar model planes with two different weights but their wing loading is the same, will they have similar flight characteristics? I'm looking at a few planes out there (drooling over would be more like it). Some have a higher flying weight than others but have a similar (if not lighter!) wing loadings than the ones with a lighter flying weight.

Thanks for the help!

Eric

If everything else is pretty much the same (airfoils, profile, etc.) they should have similar characteristics, but if they're different weights with the same wing loading they're not the same (heavier planes got more wing area) so they'll fly differently. How's that for a non answer (best I could do on short notice).

Mike

Just sat down and looked at the new Quiet Flyer and it jogged my memory. Check the cubic wing loading (cube the wing area then take the square root) and divide by the weight. If the planes are similar and the cubic wing loading's about the same they should fly pretty much the same.

Mike

Mike,

That is VERY interesting! I had never heard that one before. With that new bit of info that'll mean I'll have to push something out of my brain to make room for it. Ha-ha-ha! But seriously I do appreciate the info. I'll have to apply the calculations to the planes I'm looking at and see how they, ahem, weigh in. Each plane I'm looking at are pretty much all the same in terms of airfoil, engines, etc. Some are heavier while others are lighter. I can't wait to apply this new formula to see how they turn out!

Thanks again for the info!

Eric

Correction, divide the weight by the result.

Mike

So it's the weight divided by the square root of the area cubed? Is that correct?

Thanks again! I greatly appreciate the info!

Eric

Eric -

Lets assume a wingloading of 23 oz/sq ft wing loading.
A park flyer would fly like a brick.
A 40 size airplane will fly OK.
A quarter scale would be very light.

feihu

the wing loading is literally how many Ounces (or pounds) each sqaure inch (or suqare foor) of the wing must lift to make the airplane fly. (a 100 Sq in wing on a 10 oz airplane... 100 Sq inches must lift 10 ounces... 1 Sq Inch must lift .1 ounce.... .1 Oz per Sq In.)
so if you've got 2 different sizes of the same airplane, say a .40 and a .90,
if the .90 has twice the wing area and weighs twice as much as the .40 version, the wing loading on both airplanes will be the SAME,
but the bigger airplane is going to fly better because of reynolds effect. (bigger airplanes fly better than little ones do.)