wing loading
05-01-2013, 07:14 PM
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wing loading
I've recently added pontoons to a 60 size sport/3D nitro airplane, and wonder if it will ever leave the
water. The plane weighs 11 lbs. with a wing loading of 34. Using a OS .91 Fx and a 14-6 prop.
The span is 56" with a 16.5 chord tapering to 10" at the wing tip. That 34 loading seems to be way
too much! Please send your comments and many thanks.
water. The plane weighs 11 lbs. with a wing loading of 34. Using a OS .91 Fx and a 14-6 prop.
The span is 56" with a 16.5 chord tapering to 10" at the wing tip. That 34 loading seems to be way
too much! Please send your comments and many thanks.
05-02-2013, 01:29 AM
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RE: wing loading
might not have the same vertical performance, but if you get the float angles tuned in it should go, just dont force it off the water, itll go when its ready. once in the air floats make enough lift to fly themselves
05-02-2013, 05:44 AM
#3
RE: wing loading
Depends also on the width (beam) of your floats. For that model I'd go for a pair of floats about 3" wide, or just over.
If your floats are too wide (say 5" wide each) then your model will be up on the plane at quite a low speed. It will be planing along, and bouncing from wave to wave, and bouncing up into the air, at far too low a speed to fly. So it will tend to bounce into the air, stall, and cartwheel into the water.
If you find this is the case, try using narrower but deeper (and/or longer) floats.
For a model of that weight you want floats which stick out ahead of the prop by about 10% of their length, with the step just aft of the aircraft CG.
The total length times max width times max depth of each float should be about 600 to give the required buoyancy.
Maybe something like 40" long by 3.25 wide by 4.6" deep
On the website
www20.brinkster.com/gvmac/
look under "Alasdair's Section" for an article on float design and construction.
If your floats are too wide (say 5" wide each) then your model will be up on the plane at quite a low speed. It will be planing along, and bouncing from wave to wave, and bouncing up into the air, at far too low a speed to fly. So it will tend to bounce into the air, stall, and cartwheel into the water.
If you find this is the case, try using narrower but deeper (and/or longer) floats.
For a model of that weight you want floats which stick out ahead of the prop by about 10% of their length, with the step just aft of the aircraft CG.
The total length times max width times max depth of each float should be about 600 to give the required buoyancy.
Maybe something like 40" long by 3.25 wide by 4.6" deep
On the website
www20.brinkster.com/gvmac/
look under "Alasdair's Section" for an article on float design and construction.
05-05-2013, 12:46 PM
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RE: wing loading
Thanks Otter Guy and Alasdair for the very helpful information! I'll follow your advice
and give it a try at our flying site just north of Healdsburg, California. I belong to the
Wine Country Flyers radio control club (see Internet). Healdsburg is about 60 miles
north of San Francisco. CA. Again, many thanks. Ollie Burns
and give it a try at our flying site just north of Healdsburg, California. I belong to the
Wine Country Flyers radio control club (see Internet). Healdsburg is about 60 miles
north of San Francisco. CA. Again, many thanks. Ollie Burns
