What is a good target wing loading fo a 50cc size aerobatic plane like a Yak or an Edge, etc.?

For 3D, probably as light as you can get, maybe I should also ask what would be considered a high wing loading for 3D?

A plane that weighs 16 pounds and has 1390 squares will give ya about 26.5 oz/ft wingloading.

A plane with 1600 squares and weighs 17 pounds will give ya about 24.5 oz/ft wingloading.

The BME Yak is a popular 3D model and it has about 1450 squares. Projected weight is 16.5 pounds on the high end. That works out to about 26oz/ft.

Aerobatic planes can fly with wingloading numbers up in the 30's but for 3D, I think you want it as much under 28 as you can get.

Consider a standard trainer (Sig LT-40) has about 16oz/ft wingloading. If you could get a large scale aerobatic plane down to 16oz/ft--you'd be in 3D heaven.

I have no intensions off stealing your thread, but can someone please explain to me how to calculate wing loading?

Typically, wing loading is in ounces per square foot.

To get this you usually need to convert lbs to oz. Multiply the weight in lbs by 16 and you get oz.

To get square feet you usually need to convert from sq inches - so divide the sq inches by 144.

To do it quickly use this formula: 2304 x (plane weight in lbs) / (wing area in sq inches)

If a plane weighs 16.5 pounds--all you do is multiply that by 16ounces.

16.5 x 16 = 264 -- weight of plane in ounces

To convert square inches of wing area into square feet, simply divide the square inches by 144. There is 144 square inches in a square foot. 12 x 12 = 144

So, if the plane has 1492 square inches. all you do is divide that by 144.

1492 / 144 = 10.3611111111 square feet. Round to 10.36

Now take your total ounces ( 264 ) and dived it by the square feet ( 10.36 )

264 / 10.36 = 25.492625 In my world, that rounds to 25.5 ounces/square foot wingloading.

But, it's not always that simple. Some manufacturers/distributors only give you the actual square inches of the wing panels and NOT the area of the fuse in between the wings. That area DOES count in the equation. It's flying the plane.

So, if your only calculating wing panels--your wingloading will seam kinda high. Figure the root of most 28% planes is about 20--21" cord. Now figure the width of the fuse where the wings are. Usually in the neighborhood of about 8--10" wide.

20" cord X 10" width = 200.

That yields another 200 square inches of wing area. That will have a drastic effect on your wingloading numbers.

We got 25.5 ounces/foot wingloading on the example above. Now lets take out 200 square inches and do the math again.

1292 square inches / 144 = 8.972 square feet of wing

The plane weighs the same, so take your plane weight in ounces ( 264 ) and divide it by the square feet ( 8.972 )

264 / 8.972 = 29.42487 Round to 29.4 ounces/square feet wingloading.

Thats a difference of about 4oz per square foot on the wingloading. And that was simply by ommitting the area in the fuse between the wings.

Be careful how you calculate.

I have no idea how to calculate metric. [sm=spinnyeyes.gif]

Man, that was more complicated than I thought!
But it seems to make sense now, so thank you so much
Now I can brag about wing loading calculations, lol